bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECT OF CYSTINE AND GLYCOCOLL ON THE OXIDATION OF SODIUM LACTATE BY HYDROGEN PEROXIDE
Authors: Ray George B.
Published: May 2004

The rate of production of CO2 from sodium lactate when treated with H2O2 may be increased by the addition of a compound containing a sulfhydryl group, i.e. cystine.

A small part of this increase in rate of CO2 is due to the action of the amino group as shown by the action of glycocoll.

The results tend to show that the mode of action of H2O2 is one of dehydrogenation and that the action of the cystine is comparable to the Atmungskörper of Meyerhof.
ON STEREOTROPISM IN TENEBRIO LARVÆ
Authors: Crozier W. J.
Published: May 2004

Larvæ of Tenebrio while creeping show homostrophic responses, and stereotropic orientation to lateral contacts. Homostrophic orientation is inhibited by stereotropism. Both depend upon the anterior portion of the central nervous system. Stereotropic orientation due to unilateral contact, particularly at the anterior end, persists briefly after the cessation of the contact.

Equal posterior bilateral contact of the body obliterates stereotropic bending. Unequal posterior bilateral contacts lead to orientation through an angle roughly proportional to the differences in contact areas. Functional symmetry in such responses is not disturbed by asymmetrical distribution of the body "hairs."

The stereotropic orientation undergoes reversal of direction, central in origin, when the stimulation is sufficiently intense.

Stereotropic response, leading to maintained lateral contact with a surface or to bending when the end of such a surface has been passed, is inhibited by a definite intensity of light.

These findings (1) round out the demonstration that stereotropism is truly of a tropistic character, and (2) make possible the understanding of conduct in a case involving the participation of contact stimulation, phototropism, temperature, and homostrophy.
NUTRITIONAL STUDIES ON THE CONFUSED FLOUR BEETLE, TRIBOLIUM CONFUSUM DUVAL
Authors: Chapman Royal N.
Published: May 2004

The confused flour beetle (Tribolium confusum) was chosen for this study because it lives in a food which ordinarily contains no living organisms. The death rates are greater in cultures which are handled daily than in those which are not handled but when all are handled alike the results are comparable.

The results from experiments with individual beetles in various kinds of flour were plotted with instars (larval stages) on the ordinate and time in days on the abscissa, using the results from control experiments in wheat flour to determine the length of the various instars from an "x = y" formula. The curves of development were found to be straight lines throughout all but the last instar. The curve for the last instar during which the larva transformed deviated from the straight line in certain foods, notably rice flour.

When mass cultures were used the death and transformation curves were plotted for each synthetic food. A comparison of the curves from wheat flour and the synthetic foods shows that the first parts of the curves are very much alike in all cases and that a few resemble the control in every respect except that the transformation curve has been moved back for a considerable time.

The death curves for the mass cultures are not smooth but show sudden increase in death at approximately the times of molting. These curves may therefore be compared with the records from individual beetles.
CHANGES IN THE STABILITY AND POTENTIAL OF CELL SUSPENSIONS
Authors: Eggerth Arnold H.
Published: May 2004

1. Human and sheep erythrocytes, when placed in 0.01 N buffer solutions at reactions more acid than pH 5.2, undergo a progressive change in potential, becoming less electronegative or more electropositive. This change usually occurs within 2 hours at ordinary room temperatures. It did not occur when rabbit erythrocytes were used.

2. This change is due primarily to the liberation of hemoglobin from some of the cells.

3. Hemoglobin, even in very low concentrations, markedly alters the potential of erythrocytes in the more acid reactions. This is due to a combination between the electropositive hemoglobin and the erythrocytes. The effect of the hemoglobin is most marked in the more acid solutions; it occurs only on the acid side of the isoelectric point of the hemoglobin.

4. The isoelectric point of erythrocytes in the absence of salt, or in the presence of salts having both ions monovalent, occurs at pH 4.7. This confirms the observations of Coulter (1920–21). Divalent anions shift the isoelectric point to the acid side.

5. The effect of salts on the potential of erythrocytes is due to the ions of the salts, and is analogous in every way to the effect of salts on albumin-coated collodion particles, as discussed by Loeb (1922–23).
THE AGGLUTINATION OF RED BLOOD CELLS
Authors: Northrop John H. , Freund Jules
Published: May 2004

1. Unsensitized sheep cells suspended in sugar solutions are agglutinated by electrolytes whenever the potential is depressed to 6 millivolts or less, except in the case of MgCl2 or CaCl2.

2. With these salts no agglutination occurs although there is practically no potential. The presence of these salts prevents acid agglutination. This is presumably due to a decrease in the "cohesion" between the cells.

3. Cells which have been sensitized with specific antibody, ricin, colloidal stannic hydroxide, or paraffin oil, are agglutinated whenever the potential is decreased below about 12 millivolts.

4. The agglutination by electrolytes is therefore primarily due to a decrease in the potential whereas agglutination by immune serum, ricin, etc., is due primarily to an increase in the critical potential.
WAVE LENGTH OF LIGHT AND PHOTIC INHIBITION OF STEREOTROPISM IN TENEBRIO LARVÆ
Authors: Crozier W. J.
Published: May 2004

A definite intensity of white light is required (about 136 m.c.) to produce negative phototropic orientation of creeping Tenebrio larvæ away from contact with a vertical glass surface. This gives a measure of stereotropism in terms of phototropism, or reciprocally.

The effectiveness of light for the suppression of stereotropism varies with wave length. It is therefore simple to obtain a measure of the relation between wave length and stimulating efficiency in this case of phototropic orientation.

By determinations of the minimal energy required to inhibit stereotropism with different regions of the spectrum, it is found that the maximum effectiveness is sharply localized in the neighborhood of 535µµ.

The curve connecting stimulating efficiency with wave length, while giving a picture of the effective absorption by the photosensory receptors, probably does not permit accurate characterization of the essential photosensitive material.
THE EFFECT OF ULTRA-VIOLET, X-RAY, AND RADIUM RADIATION ON THE TOXICITY OF NORMAL BLOOD
Authors: Macht David I. , Hill Eben C.
Published: May 2004

While the number of experiments performed is perhaps somewhat limited the results obtained were quite definite and warrant the following conclusions. The toxicity of normal blood for living plant protoplasm as studied on the growth of Lupinus albus seedlings is definitely influenced by various radiations. Ultra-violet rays produce no effect on normal blood or may even render it slightly less toxic. Roentgen rays render normal blood more toxic. The toxicity is greater in the case of the blood plasma as compared with the blood cells and a more toxic effect is produced with the Coolidge tube as compared with the gas tube. Radium emanations in the few experiments performed produced changes very much the same as those given by the x-rays.
THE EFFECT OF POTASSIUM ON THE ACID METABOLISM OF SURVIVING SKELETAL AND CARDIAC MUSCLES OF THE FROG
Authors: Griffith Fred R.
Published: May 2004

The potassium contraction of skeletal muscle and relaxation of cardiac muscle have been correlated with the carbon dioxide and total acid production of these tissues.

1. The immersion of surviving sartorius muscles of the frog in isotonic potassium chloride solution causes a marked increase in the rate of acid production.

2. It is probable that carbon dioxide is the principal acid involved in the above effect.

3. The immersion of surviving cardiac muscle of the frog in isotonic potassium chloride solution causes a pronounced depression in the rate of survival acid production.

4. Reasons are given for believing that these changes in metabolism may be independent of the stimulation and inhibition of contraction which potassium simultaneously produces in these tissues.
THE ALKALINE ISOPOTENTIAL POINT OF THE BACTERIAL CELL
Authors: Winslow C.-E. A. , Shaughnessy H. J.
Published: May 2004

Irregularities in migration velocity of bacterial cells in the highly alkaline solutions are due to the buffering effect of the cells upon the immediately adjacent zone of menstruum. Consistent results can be obtained by shaking the suspension thoroughly before placing it in the electrophoretic cell.

When observed in this way both Bacillus cereus and Bacterium coli show an isopotential point near pH 13.5, that for Bacillus cereus being slightly below, and that for Bacterium coli slightly above this point. At more alkaline reactions the cells acquire a positive charge which increases with further increase in pH to very high values.
A NOTE ON THE RELATIVE PHOTOSENSORY EFFECT OF POLARIZED LIGHT
Authors: Crozier W. J. , Mangelsdorf A. F.
Published: May 2004

Experiments were made to compare the stimulating effectiveness of vertically and horizontally polarized lights and non-polarized lights of equal intensity upon phototropic movements of the beetle Tetraopes tetraopthalmus; and to compare the effectiveness of two light beams polarized at right angles to one another upon phototropic orientation of the land isopod Cylisticus convexus. Tetraopes is positively, and Cylisticus, negatively phototropic. Tests were also made of the intensities of horizontally and of vertically polarized light required to inhibit stereotropism in larvæ of Tenebrio. Under the conditions of the tests, no certain qualitative effect connected with polarization could be detected.
THE LOCOMOTION OF LIMAX
Authors: Crozier W. J. , Pilz G. F.
Published: May 2004

Pedal progression of the slug Limax maximus was studied to obtain relations between wave velocity on the sole of the foot, wave frequency, the advance due to a single wave, and the velocity of vertically upward creeping. Each of the first three quantities is directly proportional to the simultaneous velocity of progression. Under comparable conditions, that is when work is done at a constant rate, the frequency of pedal waves is influenced by the temperature according to the equation of Arrhenius, with µ = 10,700 (Q10 for 11° to 21° = 2.1). The velocity of a single wave must have very nearly the same "temperature characteristic," which is found also in another case of nerve net transmission (in Renilla).
THE KINETICS OF TRYPSIN DIGESTION
Authors: Northrop John H.
Published: May 2004

The rate of digestion of concentrated casein solutions by low concentrations of trypsin at 0° has been followed. Under these conditions the enzyme is inhibited by the product of the reaction and under certain conditions this effect should lead to Schütz's rule, i.e. the amount of hydrolysis should be proportional to the square root of the product of the time into the enzyme concentration. This is the result obtained. Both Schütz's rule and Arrhenius' equation fail to hold accurately owing to the incorrect relation assumed to hold between the rate of hydrolysis and the substrate concentration.
MEMBRANE EQUILIBRIA AND THE ELECTRIC CHARGE OF RED BLOOD CELLS
Authors: Coulter Calvin B.
Published: May 2004

It has been shown, within the probable limit of error of the methods of measurement employed, that the Donnan equilibrium determines the distribution of H and Cl ions between the cell and the surrounding fluid. This equilibrium is a consequence of the impermeability of the cell membrane to the inorganic cations of the cell. The mechanism responsible for this equilibrium is suggested as that concerned in the secretion of HCl by the cells of the gastric mucosa. If the salt concentration of the medium is low there may result from the Donnan equilibrium a thermodynamic P.D. of considerable magnitude. In the presence of low concentrations of electrolytes, this P.D. is to be regarded as positive in sign at reactions of the medium at which the cataphoretic charge of the cell is negative in sign. The explanation of this discrepancy in sign of charge may lie in the existence at an outer phase-boundary of a second Donnan equilibrium the nature of which is determined by the ionization of the protein of the cell membrane.
CRITICAL THERMAL INCREMENT FOR THE MOVEMENT OF OSCILLATORIA
Authors: Crozier W. J. , Federighi H.
Published: May 2004

In a species of Oscillatoria exhibiting movement of type suitable for exact measurement the velocity of linear translatory motion is found to be controlled by the temperature (6 – 36°C.) in accordance with Arrhenius' equation for irreversible reactions. The value of the critical increment (µ) is 9,240. The extreme variates in series of measurements at different temperatures yield the same value of µ. The velocity of movement is therefore regarded as determined by the velocity of an underlying chemical process, controlled by the temperature and by the amount of a substance (? catalyst) whose effective quantity at any moment varies within definite limits in different filaments of the alga.

On the basis of its temperature characteristic the locomotion of Oscillatoria is compared with certain other processes for which this constant is calculated.
PHOTOTROPIC CIRCUS MOVEMENTS OF LIMAX AS AFFECTED BY TEMPERATURE
Authors: Crozier W. J. , Federighi H.
Published: May 2004

1. The theory of animal phototropism requires for particular instances a knowledge of the action of light as exerted through each of two bilaterally located receptors functioning singly. The measurement of "circus movements" which this involves must be concerned with such aspects of the reaction as are demonstrably dependent upon the effect of light.

2. The negatively phototropic slug Limax maximus exhibits very definite and continuous circus movement under vertical illumination when one eye-tentacle has been removed. The amplitude of the circling movement, measured in degrees deflection per cm. of path as an index of maintained differential tonus, is intimately related to the concurrent velocity of creeping. Analysis of the orienting mechanism is facilitated by the fact that in gasteropods such as Limax the animal creeps by means of the pedal organ, but orients (turns) by a totally distinct set of muscles in the dorsal and lateral regions of the body wall.

3. The expression of the phototropic orienting tendency, with illumination constant, is greatly influenced by the temperature. Above a zone centering at 15°, the amplitude of turning (degrees per cm. of path) is determined by the temperature in accurate agreement with Arrhenius' equation for chemical reaction velocity, with the critical increment µ = 16,820; and the rate of creeping is progressively less as the temperature rises, µ for its reciprocal being 10,900. Below 15°, the velocity of creeping becomes less the the lower the temperature, µ being again 16,800; while the amplitude of orientation is limited merely by the velocity of creeping, its reciprocal being directly proportional thereto.

4. Measurements of Limax circus movements in terms of turning deflection as function of light intensity must therefore be carried out at a temperature well above 15°.

5. The analysis provides a gross physical model of how an end-result may be influenced by temperature according to the effect of temperature upon each of several interconnected processes when the "temperature vs. effect" curves for these processes dynamically intersect.

6. It is pointed out that a certain type of unpredictability (quantative variability) in animal behavior under "normal" natural conditions probably results from dynamic equilibrium there obtaining between diverse mechanisms competing for effector control (in the present case, the creeping mechanism and that for turning, in the range 14–16°C.). It follows that the unraveling of the elements of conduct necessitates experimentation under diverse abnormal conditions favoring individual mechanism of response.
THE INFLUENCE OF OXYGEN TENSION UPON METABOLIC RATE IN INVERTEBRATES
Authors: Amberson W. R. , Mayerson H. S. , Scott W. J.
Published: May 2004

It is shown that in several of the higher invertebrate animals, oxygen consumption is directly proportional to the oxygen tension in the sea water, over a wide range.
SOME PHYSIOLOGICAL ACTIONS OF CYANIDES
Authors: Bodine Joseph Hall
Published: May 2004

1. The physiological actions of HCN and its salts appear to be due (a) to the ease with which HCN molecules penetrate living cells and then ionizing, exert their influence by means of H ions and CN ions; (b) to the weakness of HCN as an acid, which permits at neutrality or at even slight alkalinity the presence of a considerable amount of free HCN molecules in the presence of their salts; (c) to specific effects occasioned by its chemical activity.

2. The order of resistance of various protozoans to HCN resembles that of the same protozoa to CO2 and to H2S, but is the reverse of their resistance to mineral acids.

3. HCN in acid, neutral, or slightly alkaline media produces intracellular acidity because of the rapid penetration of HCN molecules into the cell.

4. HCN acts specifically on certain species of protozoa, the order of resistance of Paramecia being Paramecium caudatum > Paramecium mullimicronucleatum > Paramecium aurelia > Paramecium bursaria.
THE COMBINATION OF SALTS AND PROTEINS. I
Authors: Northrop John H. , Kunitz M.
Published: May 2004

1. It has been found that the ratios of the total concentrations of Ca, Mg, K, Zn, inside and outside of gelatin particles do not agree with the ratios calculated according to Donnan's theory from the hydrogen ion activity ratios.

2. E.M.F. measurements of Zn and Cl electrode potentials in such a system show, however, that the ion activity ratios are correct, so that the discrepancy must be due to a decrease in the ion concentration by the formation of complex ions with the protein.

3. This has been confirmed in the case of Zn by Zn potential measurements in ZnCl2 solutions containing gelatin. It has been found that in 10 per cent gelatin containing 0.01 M ZnCl2 about 60 per cent of the Zn++ is combined with the gelatin.

4. If the activity ratios are correctly expressed by Donnan's equation, then the amount of any ion combined with a protein can be determined without E.M.F. measurements by determining its distribution in a proper system. If the activity ratio of the hydrogen ion and the activity of the other ion in the aqueous solution are known, then the activity and hence the concentration of the ion in the protein solution can be calculated. The difference between this and the total molar concentration of the ion in the protein represents the amount combined with the protein.

5. It has been shown that in the case of Zn the values obtained in this way agree quite closely with those determined by direct E.M.F. measurements.

6. The combination with Zn is rapidly and completely reversible and hence is probably not a surface effect.

7. Since the protein combines more with Zn than with Cl, the addition of ZnCl2 to isoelectric gelatin should give rise to an unequal ion distribution and hence to an increase in swelling, osmotic pressure, and viscosity. This has been found to be the case.
OBSERVATIONS ON THE INJURIOUS EFFECTS OF HIGH TEMPERATURES ON FROG SKIN
Authors: Klopp John W.
Published: May 2004

1. The P.D. between the two surfaces of the skin of the frog, when measured under standardized conditions, may be used as a means of studying the phenomena of injury, recovery, and death. Injurious conditions decrease the P.D.

2. According to the severity of the injury produced by temporary exposure to high temperatures, frog skin may show, as judged by this criterion (a) complete recovery, (b) partial recovery, or (c) a progressive change leading to death.
STUDIES IN THE PHYSICAL CHEMISTRY OF THE PROTEINS
Authors: Cohn Edwin J. , Berggren Ruth E. L.
Published: May 2004

1. The methods of measuring the base-combining capacities of proteins have been considered, and the constants and corrections that are employed in their calculation have been critically examined.

2. The base-combining capacities of ten casein preparations have been determined. These differed from each other to a far greater extent than can be attributed to the experimental errors involved in their measurement and calculation. The variations were, moreover, systematic in manner, and can be explained as dependent upon the method employed in the preparation of the casein.

3. Casein that had never been exposed to greater alkalinities than those in which it exists in nature combined with approximately 0.0014 mols of sodium hydroxide per gm., while casein prepared nach Hammarsten, and casein that was saturated with base during its preparation, combined with approximately 0.0018 mols of sodium hydroxide per gm.

4. 1 mol of sodium hydroxide, therefore, combined with 735 gm. of casein that had not previously been exposed to alkaline reactions, or with 535 gm. of casein that had previously been saturated with base.

5. If the minimal molecular weight of casein, based upon its tryptophane content, is placed at 12,800, the native protein must, therefore, contain approximately eighteen acid groups, and in addition six acid groups that are released in alkaline solutions, and presumably represent internally bound groups. The total base-combining capacity therefore represents that of a substance with a molecular weight of 12,800 and containing twenty-four acid valences.

6. This base-combining capacity is no greater than can be accounted for on the basis of our knowledge of the structure and composition of casein. On the basis of a molecular weight of 12,800 casein contains at least 19 molecules of glutamic acid, 4 of aspartic, and 8 of hydroxyglutamic acid. If the amino acids in the protein molecule are bound to each other in polypeptide linkage, each of these thirty-one dicarboxylic acids should yield terminal groups. The ammonia in casein suggests that twelve of these groups are bound as amides. As many as nineteen carboxyl groups may, therefore, be free in the protein molecule.

7. Casein contains phosphorus. If this phosphorus represents phosphoric acid, and if we consider that all of the valences of this acid are either themselves free, or that they have liberated carboxyl groups by entering into the structure of the protein molecule, casein should contain nine additional acid groups.

8. Recent analytical results, therefore, indicate that casein contains at least nineteen, and possibly twenty-eight, free acid groups. The physicochemical measurements presented suggest that casein combines with base as though it contained twenty-four acid groups, of which six, or one-fourth, appear to be bound in the native protein. These experimental results are therefore in close agreement with the expectation on the basis of the classical theory of protein structure.
ON BIOLOGICAL OXIDATIONS AS FUNCTION OF TEMPERATURE
Authors: Crozier W. J.
Published: May 2004

1. The critical thermal increments are calculated for respiratory processes (O2 consumption, CO2 production) in various plants and animals. They are characteristically found to be of two, possibly three, types: µ = 11,500, and 16,100 or 16,700. The first is commonly encountered above 15°, the second below that temperature, but these relations may be reversed. (The value of µ may be significantly changed in inanition.)

2. For reduction of methylene blue by bacteria, through removal of H from succinic acid, µ = 16,700. This process (Quastel and Whetham, 1924) at constant temperature is a function of the hydroxyl ion concentration. The suggestive identity is pointed out of the critical increment for this reduction phenomenon with that deduced for biological respirations in which a dehydrogenation mechanism is supposed to be of widespread occurrence, and in connection with which Fe very likely has a catalytic rôle. The action of OH' is believed to be revealed in the value µ = 11,500, frequently obtained in connection with respiration.

3. A somewhat lower µ (16,140) is associated with the oxidation of Fe'', and may be compared with (1) that of respiration in sea urchin eggs, for which (Warburg) iron is catalyst, and (2) that for some simple reactions in which Fe is known to serve as catalyst; it is not found for oxidative reactions in which Fe is not involved.

4. The bearing of these findings is discussed in relation to the theory of functional analysis of concurrent catalyzed reactions in protoplasm. It is shown that for a number of activities in which the effects of respiration may safely be assumed, the values of the critical increments are consistent with those determined for processes of respiration.

5. The further development of these views may lead to an extremely important method of identifying controlling reactions in undisturbed living matter.
SUPPRESSION OF PHOTOTROPIC CIRCUS MOVEMENTS OF LIMAX BY STRYCHNINE
Authors: Crozier W. J. , Federighi H.
Published: May 2004

By injection with strychnine the phototropic circus movements of the slug Limax maximus may be suppressed, its phototropism abolished. The creeping activity of the foot is not in any essential way interferred with. Strychnine produces in Limax central nervous effects of the sort associated with its characteristic action. Hence, although an effect of the drug upon photoreceptors cannot be definitely excluded, the experimental result is held to demonstrate that in orientation during circus movements there occurs central "competition" between impulses resulting (1) in the release of pedal waves and (2) in the maintenance of a turning posture.
STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI
Authors: Greenberg David M. , Schmidt Carl L. A.
Published: May 2004

1. The deposition of casein on a platinum anode which takes place on the passage of a direct current through solutions of alkali caseinates was quantitatively studied, and it was found that: (a) the amount of casein which is deposited is directly proportional to the current, i.e. it obeys Faraday's law; (b) the amount of casein deposited is inversely proportional (within the limits studied) to the amount of alkali which is combined with the casein.

2. A method of determining the transport numbers of proteins insoluble at their isoelectric point has been developed.

3. A titration method for determining the amount of alkali in a casein solution is given.

4. Data from the results of transference experiments on sodium caseinate, potassium caseinate, cesium caseinate, and rubidium caseinate solutions are given. It is shown that the data are best explained on the assumption that in these solutions the carriers of the current are alkali metal cations and casein anions.

5. On the basis of our transference results an explanation is given of the results which were obtained by Robertson and by Haas in their migration experiments.
STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI
Authors: Greenberg David M. , Schmidt Carl L. A.
Published: May 2004

1. The results of conductivity experiments with alkali caseinate solutions are given and a graphical method of extrapolation, which gives a straight line, is described. The results of the conductivity experiments are shown to be in accord with the results of the previous transference experiments.

2. The change of conductivity of the alkali caseinate solutions with temperature is shown to follow a straight line relationship.

3. The high value of the mobility which was obtained for the casein ion and the high temperature gradient are discussed in relation to McBain's theory of colloidal electrolytes.
STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI
Authors: Greenberg David M. , Schmidt Carl L. A.
Published: May 2004

1. The phenomenon of protein racemization is discussed and certain deductions are made in connection with the hypothesis of Dakin to account for this phenomenon and Robertson's theory of the ionization of proteins.

2. Experimental data are given to show that the electrochemical behavior of racemic casein is not in accord with the deductions which have been drawn from the theory advanced by Robertson.

3. An analysis of the nitrogen groups of racemic casein is given and compared with a similar analysis of normal casein. From these analyses and from the electrochemical equivalent of racemic casein, it is concluded that except for the hydrolysis of amide groups, racemic casein is probably not a degradation product of casein.

4. Considerable evidence is presented against the view that the -COHN- groups take part in the reactions of the protein molecule with acids and with bases.
STUDIES ON BIOLUMINESCENCE
Authors: Harvey E. Newton
Published: May 2004

1. Small dumps of the luminous cells of Mnemiopsis cannot readily be stimulated mechanically but will luminesce on treatment with saponin solution. Larger groups of luminous cells (such as are connected with two paddle plates) luminesce on mechanical stimulation. This suggests that mechanical stimulation to luminesce occurs chiefly through a nerve mechanism which has been broken up in the small dumps of luminous tissue.

2. The smallest bits of luminous tissue, even cells freed from the animal by agitation, that will pass through filter paper, lose their power to luminesce in daylight and regain it (at least partially) in the dark.

3. Luminescence of the whole animal and of individual cells is suppressed by near ultra-violet light (without visible light).

4. Inhibition in ultra-violet light is not due to stimulation (by the ultra-violet light) of the animal to luminesce, thereby using up the store of photogenic material.

5. Animals stimulated mechanically several times and placed in ultra-violet light show a luminescence along the meridians in the same positions as the luminescence that appears on stimulation. This luminescence in the ultra-violet or "tonic luminescence," is not obtained with light adapted ctenophores and is interpreted to be a fluorescence of the product of oxidation of the photogenic material.

6. Marked fluorescence of the luminous organ of the glowworm (Photuris) and of the luminous slime of Chatopterus may be observed in ultra-violet but no marked fluorescence of the luminous substances of Cypridina is apparent.

7. Evidence is accumulating to show a close relation between fluorescent and chemiluminescent substances in animals, similar to that described for unsaturated silicon compounds and the Grignard reagents.
CONDUCTIVITY AS A MEASURE OF THE PERMEABILITY OF SUSPENDED CELLS
Authors: Brooks S. C.
Published: May 2004

The problem of determining by means of measurements of electrolytic conductance the permeability of living cells in suspension is considered in some detail and it is pointed out that several factors, usually neglected, have an important influence on the interpretation of such studies. These are:

1. The relative volume and the shape of cells, which are responsive to changes in osmotic pressure and constitution of the surrounding solution. The sources of error in various methods of determining the true volume of red blood cells in a suspension are explained. The hematocrit method appears to be the most reliable method in this case.

2. The proportion of living cells, which is especially to be regarded in the case of suspensions of bacteria. It is shown that this may be very high when appropriate cultural methods are used. The conductance of the dead cells must also be taken into account.

3. The progressive nature of the changes occurring during the course of an experiment. Approximate accuracy may be obtained by proper interpolation.

4. The conductivity of the protoplasm itself, which varies in response to variations is that of the surrounding fluid.

It is emphasized that cells, and in particular red blood cells, are not to be regarded as stable non-conducting particles, but rather as labile and as permeable to electrolytes. It is shown that the available data support this interpretation.
TEMPORARY ABOLITION OF PHOTOTROPISM IN LIMAX AFTER FEEDING
Authors: Crozier W. J. , Libby R. L.
Published: May 2004

When fed upon cooked potato the slug Limax maximus becomes for a day or more indifferent to light—its natural negative phototropism is suppressed. This effect is not produced by raw potato or other diets; it can be duplicated by injection of sugar solutions into the stomach or into the body fluids, and seems to be due to sugar absorbed during the digestion of the cooked starch. The fact is of interest particularly for the suggestion which it affords as to the explanation of fluctuations in conduct.
CRITICAL THERMAL INCREMENTS FOR RHYTHMIC RESPIRATORY MOVEMENTS OF INSECTS
Authors: Crozier W. J. , Stier T. B.
Published: May 2004

The rhythm of abdominal respiratory movements in various insects, aquatic and terrestrial, is shown to possess critical increments 11,500± or 16,500± calories (Libellula, Dixippus, Anax). These are characteristic of processes involved in respiration, and definitely differ from the increment 12,200 calories which is found in a number of instances of (non-respiratory) rhythmic neuromuscular activities of insects and other arthropods. With grasshoppers (Melanoplus), normal or freshly decapitated, the critical increment is 7,900, again a value encountered in connection with some phenomena of gaseous exchange and agreeing well with the value obtained for CO2 output in Melanoplus. It is shown that by decapitation the temperature characteristic for abdominal rhythm, in Melanoplus, is changed to 16,500, then to 11,300—depending upon the time since decapitation; intermediate values do not appear. The frequency of the respiratory movements seems to be controlled by a metabolically distinct group of neurones. The bearing of these results upon the theory of functional analysis by means of temperature characteristics is discussed, and it is pointed out that a definite standpoint becomes available from which to attempt the specific control of vital processes.
THYROXIN AS A DEPRESSANT OF THE DIVISION RATE OF PARAMECIUM
Authors: Torrey Harry Beal , Riddle Matthew C. , Brodie J. L.
Published: May 2004

In concentrations of 1:104, 1:105, 1:106, in alkaline solution with a hydrogen ion concentration approximating that characteristic of normal human blood, thyroxin acts like total thyroid in accelerating certain metabolic processes in Paramecium, notably those connected with the phenomena of excretion.

Unlike total thyroid, thyroxin depresses the division rate of Paramecium, the degree of depression varying directly with its concentration.

This depression of the division rate is due to the action of the thyroxin directly on Paramecium, not to a modification of the food supply.
THE RELATION OF THE STABILITY OF PROTOPLASMIC FILMS IN NOCTILUCA TO THE DURATION AND INTENSITY OF AN APPLIED ELECTRIC POTENTIAL
Authors: Lund E. J. , Logan G. A.
Published: May 2004

1. The experiments demonstrate that when a constant electric potential of sufficient intensity is applied to Noctiluca, the protoplasmic films which represent a part of the visible continuous phase of the cytoplasm and plasma membrane at the surface of the cell, become unstable and break down, thus releasing the acid contents of one of the internal discontinuous phases present in the cytoplasm of Noctiluca. This process which occurs first at anode then at the cathode side of the cell, appears to be a selective deemulsification or coalescence similar to that at the surface of an emulsion having a viscous continuous phase.

2. The experiments demonstrate that Nernst's equation

See PDF for Equation

which expresses approximately the relation of duration and intensity of a constant electric current to threshold stimulation of striated muscle, applies equally well to the process of anodal coalescence in Noctiluca.

3. Anodal and cathodal coalescence have different thresholds, due to the fact that the semipermeable plasma film at the surface of the cell is asymmetric with respect to the direction of the applied current. Attention is called to the possible relation between this phenomenon and the conditions occurring at the synapse between neurons.

4. The stability of the protoplasmic films in relation to the applied electric potential is greater in young cells than in old cells, or in other words the threshold intensity of the stimulus is higher for young than for old cells.

5. Attention is called to the occurrence in the same cell of different receptor-affector mechanisms having a corresponding difference in intensity threshold when an electric current is acting as a stimulus.
FACTORS AFFECTING TRANSMISSION AND RECOVERY IN THE PASSIVE IRON NERVE MODEL
Authors: Lillie Ralph S.
Published: May 2004

1. The speed of transmission of the activation wave along passive iron wires enclosed in glass tubes containing dilute (70 per cent) nitric acid increases with the conductivity (sectional area) of the column of electrolyte but at a slower rate. The speed is closely proportional to the square root of the conductivity

See PDF for Equation.

The reasons for this relationship are discussed and an explanation is proposed.

2. The recovery of transmissivity after the passage of an activation wave is gradual and follows a characteristic course. After an interval of partial or decremental transmission (having a high temperature coefficient and lasting several minutes at 20°), the wire recovers its power of transmitting an activation wave for an indefinite distance. In such a recovered wire the speed of transmission is at first slow and increases by degrees up to a maximum, the increase following a curve apparently of the type vt = v0 (1 – e_kt). The approximate time required to attain this maximum (corresponding to complete recovery) at the different temperatures is 15 to 20 minutes at 20°, 30 to 45 minutes at 15°, ca. 60 minutes at 10°, and 90 minutes or more at 5°.

3. The character of the curve of recovery (the curve relating speed of transmission to interval since previous activation) agrees with the assumption that the increase in speed depends on a progressive chemical change in the molecules forming the passivating film, this change involving the transformation of (relatively) nonreactive into reactive molecules and following the course of a monomolecular reaction.

4. The temperature coefficient of the speed of transmission (between 5° and 20°) is low, of the order Q10 = 1.3 to 1.6. That of the rate of recovery, on the contrary, is high (Q10 = ca. 3). The parallel to the conditions in nerve and other transmitting protoplasmic systems is pointed out and discussed.

5. Passive wires enclosed in acid-containing continuous and interrupted glass tubes immersed in a large volume of acid exhibit characteristic phenomena of distance action; under appropriate conditions the velocity of transmission of the activating influence between different areas may thus be greatly increased. Characteristic instances are cited and some possible physiological parallels are pointed out.
NEUROID TRANSMISSION IN CILIATED EPITHELIUM
Authors: Wyman Jeffries
Published: May 2004

Evidence from several sources indicates that there is present in certain types of ciliated tissue a primitive form of conduction regulating the rate of beat of the cilia. (Kraft, 1890; Engelmann, 1898). A similar type of conduction has been observed by Parker (1910) in the sponge Stylotella. In the foregoing experiments a study was made of such conduction in the ciliated tissue of the gills of the clam Unio. Observations were made on the effects of temperature changes on the rate of beat of cilia adjacent to areas not themselves directly influenced. The following results were obtained.

1. The transmission through the gill of the effects of warmth applied locally is apparent through increased rate of ciliary beat on adjacent gill tissue in all directions from the region of application. Effects are not observed laterally at a distance greater than 9 to 11 mm. from the nearest edge of the stimulated area. The narrowness of the gill makes it impossible to determine the vertical limits of the transmission.

2. Effects of low temperatures are not observable beyond the limits of the region of direct application.

These results differ from those of Kraft in tissue from the frog's pharynx, where conduction was shown to take place only down a row of beating cilia. On the other hand they agree with his results in indicating that the effects of warmth only are transmitted.

The phenomenon might be explained by the stimulating effect of the action current of the directly excited cilia on the neighboring relatively quiet cilia. A similar explanation has been offered by Lillie for waves of coordinated beating in the rows of swimming plates of ctenophores. Such an explanation, though in accord with the work on Unio, is inconsistent with certain of the observations of Kraft on the tissue from the frog's pharynx.
ON THE IMPORTANCE OF MAINTAINING CERTAIN DIFFERENCES BETWEEN CELL SAP AND EXTERNAL MEDIUM
Authors: Osterhout W. J. V.
Published: May 2004

A striking difference exists between the internal and external solution in the case of Valonia macrophysa. If this difference is abolished by placing cells in their own sap most of them quickly die.

There is some ground for believing that the maintenance of differences between the sap and the external medium is of importance for vital processes.

The sap of Valonia macrophysa is not a balanced solution in the ordinary sense and the question may be raised whether in general the interior of the cell requires a balanced solution in order to maintain life: or it may be that we must distinguish between internal and external balanced solutions.
THE TEMPERATURE CHARACTERISTIC FOR PHARYNGEAL BREATHING RHYTHM OF THE FROG
Authors: Crozier W. J. , Stier T. B.
Published: May 2004

The frequency of the pharyngeal respiratory rhythm of frogs exhibits a critical thermal increment µ = 8,800 calories. At about 15° irregularities are apparent, which may be reduced by continued adaptation to room conditions. The frequency depends upon a process possibly synaptic in locus and apparently belonging among the group of respiratory reactions. Its temperature characteristic sharply separates this process from those reactions known to be catalyzed by H ion.
THE MECHANISM OF CHANGE IN RESISTANCE OF ERYTHROCYTES TO HYPOTONIC SALT SOLUTIONS
Authors: Brooks S. C.
Published: May 2004

Ashby's work on the effects of KCl and NaCl on the resistance to hypotonic hemolysis of K•-rich and K•-poor erythrocytes has been repeated with great attention to purity of materials and refinement of technique. The results fail to agree with those of Ashby.

1. KCl produces greater loss in resistance to hypotonic hemolysis than does NaCl, irrespective of the species of the animal from which the cells are taken.

2. While cases of an increase in resistance have been encountered in my experiments, they are either very slight, or else the particular determination is subject to very great uncertainty. The great increases in resistance found by Ashby are not even approached in any of the present series of experiments.

3. Ashby's generalization that KCl and NaCl have opposite effects on red blood cells, and that the sense of these effects depends on whether the cell is K•-rich or K•-poor is not substantiated.
HYDROGEN ION CONCENTRATIONS IN THE BLOOD OF INSECTS
Authors: Glaser R. W.
Published: May 2004

The range of pH values for the blood of grasshoppers and of houseflies is 7.2 to 7.6. The range of values for roaches is 7.5 to 8.0. The range for Malacosoma americanum is 6.4 to 7.4; and the range for Bombyx mori is 6.4 to 7.2. From the work of other investigators and from the writer's results, it is apparent that the pH of insect blood, in general, may vary between 6.4 and 8.0. In the forms observed no correlation exists between blood pH and age, nor between pH and metamorphosis.
CONTRASTS IN THE CELL SAP OF VALONIAS AND THE PROBLEM OF FLOTATION
Authors: Osterhout W. J. V. , Dorcas M. J.
Published: May 2004

The marine alga Valonia macrophysa contains in its cell sap K and Na in the proportion of 5.72 to 1. In a form regarded as closely related, Valonia ventricosa, growing in similar environment, the ratio of K to Na is as 0.0278 to 1. The former contains no Mg but in the latter it is present. There are other differences in the composition of the sap.

These differences bring about a remarkable contrast in behavior in that Valonia ventricosa floats in sea water while Valonia macrophysa sinks.
CARBON DIOXIDE FROM THE NERVE CORD OF THE LOBSTER
Authors: Parker G. H.
Published: May 2004

1. The nerve cord of the lobster (Homarus americanus Milne-Edwards) is very delicate and can be used as a living preparation for only a few hours after its removal from the animal.

2. During the first hour or so after removal it discharges CO2 at a steadily decreasing rate beginning at about 0.20 mg. CO2 per gram of cord per minute and ending at about 0.07 mg.

3. This discharge exhibits a steady decrease in rate and is not divisible into a period of gush and a period of uniform outflow as with the lateral-line nerve of the dogfish. It terminates in a very few hours with the complete death of the cord.

4. Both handling and cutting the cord temporarily increase the rate of CO2 output.

5. The stimulated cord discharges CO2 at a rate about 26 per cent higher than that of the quiescent cord, an increase of about 1.6 times that of the increase observed in the lateral-line nerve of the dogfish under similar circumstances.
THE INHIBITION OF CYPRIDINA LUMINESCENCE BY LIGHT
Authors: Harvey E. Newton
Published: May 2004

The luminescence of Cypridina luciferin-luciferase solution is inhibited by illumination from a carbon arc of 15,000 foot candles in between 1 and 2 seconds. The blue to violet rays are the effective ones, the limits lying somewhere around 4,600 Å. u. to 3,800 Å. u. The luciferin, not the luciferase, is the substance affected by the light. The effect is partially reversible in the dark. The chemiluminescences obtained by oxidizing phosphorus, lophin, and chlorphenylmagnesium bromide are not inhibited by light under the above conditions.
TEMPERATURE CHARACTERISTIC FOR HEART BEAT FREQUENCY IN LIMAX
Authors: Crozier W. J. , Stier T. B.
Published: May 2004

The temperature characteristic for the frequency of the heart beat in quiescent Limax maximus is µ = 16,300 calories. This value agrees well with that obtained for certain neurogenic activities of the parietal musculature of this gastropod.
CRITICAL THERMAL INCREMENTS FOR OXYGEN CONSUMPTION OF AN INSECT, DROSOPHILA MELANOGASTER
Authors: Orr Paul Rudbert
Published: May 2004

The critical thermal increments are calculated for oxygen consumption in the pupae of the "wild type" fruit fly, Drosophila melanogaster, and are found to be of two types: µ = 11,500 and 16,800; above 15°C. the first value is obtained, the second, below this temperature.
THE CHROMOSOMES OF PARTHENOGENETIC FROGS AND TADPOLES
Authors: Parmenter Charles L.
Published: May 2004

1. This paper presents cytological observations upon Dr. Loeb's parthenogenetic frog material, with considerations upon the mechanism by which the diploid number and both sexes may be produced.

2. Both sexes of adults and tadpoles are present.

3. The chromosome number is diploid and probably 26 in both sexes. Sex chromosomes cannot be distinguished.

4. The chromosome numbers observed by other authors in parthenogenetic frog material are haploid, diploid, and variable. Their significance is considered.

5. The mechanism producing the diploid number, based on European observations, appears to be a doubling of the haploid number at some time after the second polar body is given off.

6. Overripeness may be a factor in producing both sexes of parthenogenetic frogs and tadpoles.

7. Genetic data indicate that the normal male is digametic and that there are differences of potency between male and female factors for sex which vary in frogs of the two races and in strains within the race. These differences have been interpreted by Witschi as forming a series of multiple allelomorphs.