bluuebunny/crossref_metadata_2025 huggingface dataset:
EXIT OF DYE FROM LIVING CELLS OF NITELLA AT DIFFERENT pH VALUES
Authors: Irwin Marian
Published: May 2004

Experiments on the exit of brilliant cresyl blue from the living cells of Nitella, in solutions of varying external pH values containing no dye, confirm the theory that the relation of the dye in the sap to that in the external solution depends on the fact that the dye exists in two forms, one of which (DB) can pass through the protoplasm while the other (DS) passes only slightly. DB increases (by transformation of DS to DB) with an increase in the pH value, and is soluble in substances like chloroform and benzene. DS increases with decrease in pH value and is insoluble (or nearly so) in chloroform and benzene.

The rate of exit of the dye increases as the external pH value decreases. This may be explained on the ground that DB as it comes out of the cell is partly changed to DS, the amount transformed increasing as the pH value decreases.

The rate of exit of the dye is increased when the pH value of the sap is increased by penetration of NH3.
TEMPERATURE AND FREQUENCY OF HEART BEAT IN THE COCKROACH
Authors: Fries E. F. B.
Published: May 2004

The frequency of pulsation of the intact heart in nymphs (final (?) instar) of Blatta orientalis L. increases with the temperature according to the equation of Arrhenius. The constant µ has typically the same value, within reasonable limits of error, as that (12,200) deduced for other, homologous activities of arthropods where the rate of central nervous discharge is perhaps the controlling element, namely 12,500 ± calories for temperatures 10–38°C. Below a critical temperature of about 10° a change to a higher value of the temperature characteristic occurs, such that µ = 18,100 ±. Exceptionally (one individual) µ = 14,100 ± over the whole range of observed temperature (4.5–28°).

The quantitative correspondence of µ for frequency of heart beat in different arthropods adds weight to the conception that this constant may be employed for the recognition of controlling processes.
THE GEOTROPIC CONDUCT OF YOUNG RATS
Authors: Crozier W. J. , Pincus G.
Published: May 2004

Young rats, old enough to creep well but before the eyelids are open, orient and move upward upon an inclined surface. The angle of geotropic orientation on such a surface (θ) is proportional to the logarithm of the component of gravity parallel to the inclined plane. This result is compared with the scanty information available for other animals; there is indication that it may be generally valid. The precision of the orientation, measured by the percentage dispersion of the individual measurements, also increases in proportion to the logarithm of this component. The cosine of the angle of orientation decreases very nearly in proportion to the sine of the angle of inclination. A possible interpretation of this is given as involving the idea that upward orientation ceases when the differential pull of the body weight upon the opposed legs reaches a threshold value. Attaching weights (W) to the tail causes θ to increase, and in proportion to log W.
THE PENETRATION OF BASIC DYE INTO NITELLA AND VALONIA IN THE PRESENCE OF CERTAIN ACIDS, BUFFER MIXTURES, AND SALTS
Authors: Irwin Marian
Published: May 2004

When living cells of Nitella are exposed to an acetate buffer solution until the pH value of the sap is decreased and subsequently placed in a solution of brilliant cresyl blue, the rate of penetration of dye into the vacuole is found to decrease in the majority of cases, and increase in other cases, as compared with the control cells which are transferred to the dye solution directly from tap water. This decrease in the rate is not due to the lowering of the pH value of the solution just outside the cell wall, as a result of diffusion of acetic acid from the cell when cells are removed from the buffer solution and placed in the dye solution, because the relative amount of decrease (as compared with the control) is the same whether the external solution is stirred or not.

Such a decrease in the rate may be brought about without a change in the pH value of the sap if the cells are placed in the dye solution after exposure to a phosphate buffer solution in which the pH value of the sap remains normal. The rate of penetration of dye is then found to decrease. The extent of this decrease is the greater the lower the pH value of the solution.

It is found that hydrochloric acid and boric acid have no effect while phosphoric acid has an inhibiting effect at pH 4.8 on stirring.

Experiments with neutral salt solutions indicate that a direct effect on the cell (decreasing penetration) is due to monovalent base cations, while there is no such effect directly on the dye.

It is assumed that the effect of the phosphate and acetate buffer solutions on the cell, decreasing the rate of penetration, is due (1) to the penetration of these acids into the protoplasm as undissociated molecules, which dissociate upon entrance and lower the pH value of the protoplasm or to their action on the surface of the protoplasm, (2) to the effect of base cations on the protoplasm (either at the surface or in the interior), and (3) possibly to the effect of certain anions. In this case the action of the buffer solution is not due to its hydrogen ions.

In the case of living cells of Valonia under the same experimental conditions as Nitella it is found that the rate of penetration of dye decreases when the pH value of the sap increases in presence of NH3, and also when the pH value of the sap is decreased in the presence of acetic acid. Such a decrease may be brought about even when the cells are previously exposed to sea water containing HCl, in which the pH value of the sap remains normal.
THE RÔLE OF CERTAIN METALLIC IONS AS OXIDATION CATALYSTS
Authors: Cook S. F.
Published: May 2004

1. When iron and copper are allowed to act on hydrogen peroxide and pyrogallol, enough carbon dioxide is produced to be readily measured.

2. The curve of the production of carbon dioxide may be fitted by an empirical equation, by the use of which the initial rate and the total amount of the oxidation may be determined.

3. The effect of the concentration of the reagents is different in each case, the effect varying as a fractional power of the copper and pyrogallol concentrations and as a logarithmic function of the hydrogen peroxide concentration.

4. When gold or silver is used the rate changes suddenly during the course of the reaction due to the precipitation of colloidal metal.

5. Mercury, cadmium, zinc, tin, and some other metals have no effect.

6. A theoretical set of equations is assumed to account for the action of the metals.

7. The metals are assumed to act by means of the formation of intermediate peroxides.

8. Experiments on the action of gold indicate that the metals are active in the ionic and not in the colloidal state.
AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS
Authors: Stearn Allen E.
Published: May 2004

The amphoteric behavior of a system of two amphoteric components is theoretically examined; and this is shown to correspond more nearly with certain of the physical and chemical behaviors of living tissues than does the concept of a simple ampholyte.
AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS
Authors: Stearn Allen E.
Published: May 2004

Electrometric titrations of glycine, sulfanilic acid, and various mixtures of the two have been made. These mixtures are shown to give a curve which, between their respective isoelectric points, is different from that of either substance. These mixtures have a maximum buffering power at a pH which can be theoretically calculated, and which has the characteristics of an "isoelectric point of the system."

Other pairs of ampholytes are shown to act in an analogous manner.
PHYSIOLOGICAL ONTOGENY
Authors: Murray Henry A. ,   With the Assistance of Yetta Porosowsky.
Published: May 2004

1. The previous findings that the rate of metabolism per gm. of body weight decreased with age, and that during the incubation period catabolism was mostly at the expense of fat, have been confirmed.

2. These determinations of the rate of oxygen uptake have afforded more precise values for the catabolic rate and thus permit estimations of the changes with age in the rate of absorption.
STUDIES ON ENZYME ACTION
Authors: Falk K. George , Noyes Helen Miller
Published: May 2004

The ester-hydrolyzing or lipase actions of extracts of whole mice whose ages ranged from approximately 6 days before birth to 1 year 8 months 21 days were tested on ten simple esters by the method described in previous papers. The "pictures" of the relative enzyme actions changed from a type approaching the "embryonic" as found with embryo rats and a number of tissues of rabbit embryo, to a type characteristic of the adult mouse. The mouse embryos corresponded to the rat embryos in type and differed markedly from the mouse carcinomas which have been studied. The relative and absolute enzyme actions are discussed in some detail, and the results compared with the results obtained for the life cycle of the rat.
AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS
Authors: Stearn Allen E.
Published: May 2004

From the solubility minimum the value of the basic ionization constant of sulfanilic acid is shown to lie probably between the values 1.7 x 10–15 and 3.2 x 10–15. From solubility measurements the value of this same constant is shown to lie probably between 2.0 and 2.2 x 10–15, and the isoelectric point of sulfanilic acid is thus at a cH of 0.056 or a pH of 1.25. From conductivity ratios the acid ionization constant of sulfanilic acid is shown to be 7.05 x 10–4 at room temperature (21°C.).

Calculations are made, from data published in preceding papers, of the ionization constants of glycine, Ka being 2.3 x 10–10, and Kb being 2.2 x 10–12.
GALVANOTROPISM AND "REVERSAL OF INHIBITION" BY STRYCHNINE
Authors: Crozier W. J.
Published: May 2004

The cathodically galvanotropic orientation of nemerteans, Lineus, and the anodic orientation of the gephyrean Echiurus, are reversed by the action of strychnine under conditions such that the typical "reversal of inhibition" induced by this substance is apparent. Nicotine does not give this result. Since it is necessary to assume that the strychnine effect is due to action upon the central ganglia, and since the galvanotropic effect depends upon action of the current on nerve cell bodies of the central ganglia, it must be assumed that the locus of reversal by strychnine is not perikaryal, but presumably synaptic.
ON THE EQUILIBRATION OF GEOTROPIC AND PHOTOTROPIC EXCITATIONS IN THE RAT
Authors: Crozier W. J. , Pincus G.
Published: May 2004

The intensity of light required to just counterbalance geotropic orientation of young rats, with eyelids unopened, is so related to the angle of inclination (α) of the creeping plane that the ratio log I/log sin α is constant. This relationship, and the statistical variability of I as measured at each value of α, may be deduced from the known phototropic and the geotropic conduct as studied separately, and affords proof that in the compounding of the two kinds of excitation the rat is behaving as a machine.
CERTAIN EFFECTS OF SALTS ON THE PENETRATION OF BRILLIANT CRESYL BLUE INTO NITELLA
Authors: Irwin Marian
Published: May 2004

The effect of various substances on living cells may be advantageously studied by exposing them to such substances and observing their subsequent behavior in solutions of a basic dye, brilliant cresyl blue.

The rate of penetration of the basic dye, brilliant cresyl blue, is decreased when cells are exposed to salts with monovalent cations before they are placed in the dye solution (made up with borate buffer mixture). This inhibiting effect is assumed to be due to the effect of the salts on the protoplasm.

This effect is not readily reversible when cells are transferred to distilled water, but it is removed by salts with bivalent or trivalent cations. In some cases it disappears in dye made up with phosphate buffer mixture, or with borate buffer mixture at the pH value in which the borax predominates, and in the case of NaCl it disappears in dye containing NaCl.

No inhibiting effect is seen when cells are exposed to NaCl solution containing MgCl2 before they are placed in the dye solution.

The rate of penetration of dye is not decreased when cells are previously exposed to salts with bivalent and trivalent cations.

The rate is slightly increased when cells are placed in the dye solution containing a salt with monovalent cation and probably with bivalent or trivalent cations. In the case of the bivalent and trivalent salts the increase is so slight that it may be negligible.
THE AUTODESTRUCTION OF PEPSIN IN RELATION TO ITS IONIZATION
Authors: Goulding Arthur M. , Borsook Henry , Wasteneys Hardolph
Published: May 2004

1. Evidence is presented that pepsin is a univalent acid with a value for pK of 6.85 (or a base, with pK 7.39).

2. The autodestruction of the pepsin is shown to be dependent in part upon an instantaneous irreversible change occurring in the ionized form of the enzyme (if it be an acid) or in the unionized form (if it be a base).

3. A further progressive autodestruction of pepsin at any given hydrogen ion concentration and temperature is defined by the mass law equation for a monomolecular reaction

4. The velocity of autodestruction of pepsin is directly proportional to the hydroxyl ion concentration. It is much less in the range of hydroxyl ion concentration from pOH 9.89-7.7, than in the range greater than pOH 7.7. In both of these ranges variations in pK with pOH may be represented by straight lines.
THE EFFECT OF CERTAIN RESPIRATORY INHIBITORS ON THE RESPIRATION OF CHLORELLA
Authors: Emerson Robert
Published: May 2004

Chlorella, when made heterotrophic by means of certain sugars, respires like other heterotrophic cells when subjected to the respiratory inhibitors, hydrocyanic acid, hydrogen sulfide, and carbon monoxide.

Whether the case of Chlorella is typical for green cells in general remains to be seen. Experiments with various other green organisms are being carried out, in hope of settling this point.
THERMAL INCREMENTS FOR PULSATION-FREQUENCY IN "ACCESSORY HEARTS" OF NOTONECTA
Authors: Crozier W. J. , Stier T. J. B.
Published: May 2004

The frequencies of pulsation of the "accessory hearts" in the isolated swimming-legs of Notonecta were studied in relation to temperature, with the idea that in such organs central nervous control is impossible, and that in an isolated system irreversibly proceeding toward death it might be expected that further evidence would be found regarding the supposed specific significance of critical thermal increments. A number of values of µ are found, commonly 8,200; 16,200; or 32,200; less frequently 11,400; 19,800; and 24,500. These values are definitely contrasted with that (12,300) typical for heart beat frequencies in arthropods. They exhibit interrelationships of the sorts already found in other cases. There occur also sharp irreversible changes in frequency of pulsation, which may or may not be accompanied by change of increment. The net result is held to be confirmatory of the interpretation of thermal relations proposed in earlier papers.
GEOTROPIC ORIENTATION OF YOUNG RATS
Authors: Crozier W. J. , Pincus G.
Published: May 2004

The geotropic orientation of Rattus rattus (roof rat) obeys the equations previously found applicable for Rattus norvegicus. The former is more sensitive, geotiopically, and the numerical values of the constants in the equations for the two forms are found to differ significantly. Certain consequences of this difference are pointed out.
THE PRECISE MEASUREMENT OF HEMOLYSIN
Authors: Coulter Calvin B.
Published: May 2004

A method is described for the measurement of hemolysin concentration, which makes possible exact comparison of results obtained at different times and with different specimens of erythrocytes and alexin; and gives precise values with an error not greater than 2 per cent.
THE PROTEIN ASSOCIATED WITH HEMOLYSIN IN RABBIT SERUM AND PLASMA
Authors: Coulter Calvin B.
Published: May 2004

1. The water-insoluble globulin with which hemolysin is associated, may be separated from immune serum or plasma by dilution and simple dialysis at optimal pH.

2. This optimum in plasma is influenced by the presence of the fibrinogen.

3. Fibrinogen carries no immune body, or only an insignificant amount; when present in immune body solutions in other form than fibrin gel, it depresses the hemolytic activity. The conditions for the formation of fibrin gel are similar to those for the formation of a gel by banana protein.

4. The hemolytic activity is a more labile property of the immune protein than the agglutinating activity; hemolysin is destroyed, hemagglutinin shows an apparent increase, as a result of alcohol extraction.
"GALVANOTROPISM" OF ROOTS
Authors: Navez A. E.
Published: May 2004

1. New experiments, made in such a way to eliminate as completely as possible products of polarization and the migration of such products when formed, have shown that the exhibition of galvanotropic curvature in roots is mainly dependent upon such products, since no curvature appears when they are excluded.

2. The polarization products injure the external layer of cells of the root; this allows these cells to act as electrodes directly applied on the internal tissues. The inner electrolysis produces such changes in the interior cells that they may be considered as becoming ionically different. This differential state is responsible for curvature.

3. "Galvanotropism" of roots, therefore, cannot be regarded as exactly comparable to the galvanotropic orientations of certain animals, but is essentially dependent upon injury.
THE FREE ENERGY OF NITROGEN FIXATION BY LIVING FORMS
Authors: Burk Dean
Published: May 2004

Fixation of nitrogen even with liberation of energy or free energy, will take place if either oxygen gas or hydrogen gas, or other substances, especially gases, whose standard free energies are close to zero, are involved to form either nitrates, ammonia, or cyanide, not to speak of still other compounds. It has been pointed out that there are two and only two general conditions where nitrogen fixation can require energy. These are, first, if nitrogen reacts with some compound like water with an already high negative free energy of formation and where negligible oxidation of nitrogen would occur; second, if the plant does not take advantage of working at concentrations where the process would yield free energy.

If nitrogen fixation is exothermic and free energy-yielding, how is the carbohydrate requirement of nitrogen-fixing organisms to be interpreted? Are the experimental determinations of the carbon to nitrogen ratio purely circumstantial? Is further hope given to those who may experimentally try to narrow this ratio to where the carbon used is only for the carbon requirements of general metabolism, exclusive of fixation? Do not hypotheses concerning the fixation of nitrogen in the evolutionary process, which are based on the conception that energy is required, lose some of their significance? Does it not suggest that perhaps fixation is far more universal than is supposed among living forms, particularly among the higher green plants, and thereby give encouragement to those who may wish to demonstrate this experimentally? Does it not indicate that perhaps the function of fixation is often to obtain energy for use in general metabolism? Is the general carbohydrate metabolism of the fixation forms to be regarded as being merely extremely inefficient? Or most suggestive of all, is the carbohydrate serving some unobserved function?
STUDIES ON PERMEABILITY OF MEMBRANES
Authors: Michaelis L. , Perlzweig W. A.
Published: May 2004

The theoretical aspects of the problem of sieve-like membranes are developed.

The method of preparing the dried collodion membrane is described, and the method of defining the property of a particular membrane is given. It consists of the measurement of the Co P, that is the P.D. between an 0.1 and an 0.01 M KCl solution separated by the membrane. Co P is in the best dried membranes 50 to 53 millvolts, the theoretically possible maximum value being 55 millivolts. Diffusion experiments have been carried out with several arrangements, one of which is, for example, the diffusion of 0.1 M KNO3 against 0.1 M NaCl across the membrane. The amount of K+ diffusing after a certain period was in membranes with a sufficiently high Co P (about 50 millivolts or more) on the average ten times as much as the amount of diffused Cl-. In membranes with a lower Co P the ratio was much smaller, down almost to the proportion of 1:1 which holds for the mobility of these two ions in a free aqueous solution. When higher concentrations were used, e.g. 0.5 M solution, the difference of the rate of diffusion for K+ and Cl- was much smaller even in the best membranes, corresponding to the fact that the P.D. of two KCl solutions whose concentrations are 10:1 is much smaller in higher ranges of concentration than in lower ones.

These observations are confirmed by experiments arranged in other ways.

It has been shown that, in general, the diffusion of an anion is much slower than the one of a cation across the dried collodion membrane. The ratio of the two diffusion coefficients would be expected to be calculable in connection with the potential difference of such a membrane when interposed between these solutions. The next problem is to show in how far this can be confirmed quantitatively.
A THEORETICAL CONSIDERATION OF THE ACTION OF X-RAYS ON THE PROTOZOAN COLPIDIUM COLPODA
Authors: Clark Harry
Published: May 2004

1. The theory which Crowther has advanced to account for the variation of the lethal dose of roentgen rays among the individuals of a group of Colpidium colpoda is reviewed.

2. It is shown that the use of his small-body theory to explain the small value of λe leads to certain further assumptions about the nature of the destructive effect.

3. An alternative hypothesis is discussed.
THE EFFECT OF SALT CONCENTRATION OF THE MEDIUM ON THE RATE OF OSMOSIS OF WATER THROUGH THE MEMBRANE OF LIVING CELLS
Authors: Lucke Baldwin , McCutcheon Morton
Published: May 2004

1. Using the unfertilized egg of the sea urchin, Arbacia, as osmometer, it was found that the rate with which water enters or leaves the cell depends on the osmotic pressure of the medium: the velocity constant of the diffusion process is higher when the cell is in concentrated sea water, and lower when the sea water medium is diluted with distilled water. Differences of more than tenfold in the value of the velocity constant were obtained in this way. When velocity constants are plotted against concentration of medium, a sigmoid curve is obtained.

2. These results are believed to indicate that cells are more permeable to water when the osmotic pressure of the medium is high than when it is low. This relation would be accounted for if water should diffuse through pores in a partially hydrated gel, constituting the cell membrane. In a medium of high osmotic pressure, the gel is conceived to give up water, to shrink, and therefore to allow widening of its pores with more ready diffusion of water through them. Conversely, in solutions of lower osmotic pressure, the gel would take up water and its pores become narrow.
STUDIES ON THE PERMEABILITY OF MEMBRANES
Authors: Michaelis L. , Weech A. A. , Yamatori A.
Published: May 2004

The transfer numbers of the ions of electrolytes in the dried collodion membrane, as determined in a previous paper indirectly from the E.M.F. of concentration chains, can also be determined directly by electrical transfer experiments. It is shown that the difficulties involved in such experiments can be overcome. The transfer numbers obtained by the two methods are in satisfactory agreement. The experimental results obtained in the transfer experiments furnish an additional argument in favor of maintaining the theory that the electromotive effects observed in varying concentrations of different electrolytes with the dried collodion membrane may be referred to differences in the mobilities of the anions and cations within the membrane. As was shown by the method of the previous paper, the transfer number depends largely on concentration. There are some minor discrepancies between the values of the transfer numbers obtained by the two methods which, as yet, cannot be completely explained.
MICRURGICAL STUDIES IN CELL PHYSIOLOGY
Authors: Reznikoff Paul , Chambers Robert
Published: May 2004

I. Plasmalemma.

1. Of the salts used in these experiments the anions have only a modifying effect on the cations. The dispersive action of Na and, to a lesser extent, of K, predominates. Borate increases the toxicity of Na and acetate decreases it.

2. CO2 and carbonates dissolve the plasmalemma readily.

3. Na lactate tends to dissolve the surface especially when brought into contact with it from the interior by injection.

Lactate antagonizes the stimulating effect of Ca on the plasmalemma.

II. The Internal Protoplasm.

4. Acid phosphate of Na and K, when injected, causes a membrane to form around the granular endoplasm within the ameba.

5. Na borate increases the toxicity of Na inside the cell.

6. Bubbles of CO2, injected into the cell, cause an increase of fluidity of the internal protoplasm. These bubbles shrink and disappear from the cell more readily than air bubbles.

7. The anions modify the typical cation effect. Carbonates accentuate the liquefying and solvent action of Na.

Phosphates prevent a complete rounding of the ameba caused by Na.

Lactate inhibits the solidification and pinching off effect caused by Ca.

III. Physiological Significance of Salts.

8. The buffer salts can be injected in high concentrations without toxic effects but amebæ can be immersed in them only in very dilute solutions without injury.

9. The inhibiting action of lactate and the dispersive effect of CO2, carbonates, and lactate on the plasma membrane, must be of importance in a consideration of the functions of the organism and perhaps in the production of pathological changes.
THE OXYGEN CONSUMPTION OF FROG NERVE DURING STIMULATION
Authors: Fenn Wallace O.
Published: May 2004

1. The resting rate of oxygen consumption of the excised sciatic nerve of the frog is 1.23 c.mm. of oxygen per gm. of nerve per minute.

2. During stimulation with an induction coil with 100 make and 100 break shocks per second there is an excess oxygen consumption amounting on the average to 0.32 c.mm. of oxygen per gm. of nerve per minute of stimulation, or a 26 per cent increase over the resting rate.

3. The magnitude of the excess oxygen consumption in stimulation, in agreement with the all-or-none law, is not markedly influenced by considerable variations in the intensity of stimulation.

4. Increasing the frequency of stimulation from 100 to 200 shocks per second increases the extra oxygen used only 1.12–1.18 times. The same change in frequency of stimulation increases the negative variation 1.15 times and the heat production about 1.25 times (Hill).

5. This parallelism between the excess oxygen and the negative variation argues definitely for some causal connection between the excess oxygen and the nerve impulse itself.

6. Calculation shows that the oxygen tension inside these nerves was not zero.
HYDRATION OF GELATIN IN SOLUTION
Authors: Kunitz M.
Published: May 2004

1. It was shown that the high viscosity of gelatin solutions as well as the character of the osmotic pressure-concentration curves indicates that gelatin is hydrated even at temperatures as high as 50°C.

2. The degree of hydration of gelatin was determined by means of viscosity measurements through the application of the formula

See PDF for Equation.

3. When the concentration of gelatin was corrected for the volume of water of hydration as obtained from the viscosity measurements, the relation between the osmotic pressure of various concentrations of gelatin and the corrected concentrations became linear, thus making it possible to determine the apparent molecular weight of gelatin through the application of van't Hoff's law. The molecular weight of gelatin at 35°C. proved to be 61,500.

4. A study was made of the mechanism of hydration of gelatin and it was shown that the experimental data agree with the theory that the hydration of gelatin is a pure osmotic pressure phenomenon brought about by the presence in gelatin of a number of insoluble micellæ containing a definite amount of a soluble ingredient of gelatin. As long as there is a difference in the osmotic pressure between the inside of the micellæ and the outside gelatin solution the micellæ swell until an equilibrium is established at which the osmotic pressure inside of the micellæ is balanced by the total osmotic pressure of the gelatin solution and by the elasticity pressure of the micellæ.

5. On addition of HCl to isoelectric gelatin the total activity of ions inside of the micellæ is greater than in the outside solution due to a greater concentration of protein in the micellæ. This brings about a further swelling of the micellæ until a Donnan equilibrium is established in the ion distribution accompanied by an equilibrium in the osmotic pressure. Through the application of the theory developed here it was possible actually to calculate the osmotic pressure difference between the inside of the micellæ and the outside solution which was brought about by the difference in the ion distribution.

6. According to the same theory the effect of pH on viscosity of gelatin should diminish with increase in concentration of gelatin, since the difference in the concentration of the protein inside and outside of the micellæ also decreases. This was confirmed experimentally. At concentrations above 8 gm. per 100 gm. of H2O there is very little difference in the viscosity of gelatin of various pH as compared with that of isoelectric gelatin.
STUDIES ON ENZYME ACTION
Authors: Falk K. George , Noyes Helen Miller , Lorberblatt I.
Published: May 2004

The ester-hydrolyzing or lipase actions of extracts and whole solids of trout eggs and whole trout of different ages were tested on ten simple esters by the method described in previous papers. Differences in solubility of the enzyme materials of the eggs were found. The "pictures" of the relative enzyme actions changed from a type found with immature eggs to a type which became constant for the fish after they had eaten for 2 weeks. After this, the type did not change up to the age of 4 to 5 years (the oldest trout studied). The absolute ester-hydrolyzing actions of the materials were also presented and discussed.
THE ANALYSIS OF THE DIVISION RATES OF CILIATES
Authors: Richards Oscar W. , Dawson J. A.
Published: May 2004

1. Analysis of the division rates of Paramecium aurelia (mutant), Blepharisma undulans, and Histrio complanatus grown separately in pedigree isolation culture with the same culture medium, and in the same room at any given time, for a period of 3 years, discloses a secular trend and a seasonal rhythm for each organism. The seasonal rhythm is a yearly cycle with a maximum during July.

2. After removal of the effects of trend and seasonal rhythm, no correlation is found between the division rates of the several organisms. The distribution of the division rates is then one of chance order, except for large deviations known to be associated with changes in the culture technique. Each organism has a division rate varying independently of the others.

3. Consequently, seasonal rhythm alone has forced similar variations in the division rates of these three protozoans. The seasonal effect is gradually lost when the animals are raised for several years under laboratory conditions. Examination of the literature discloses other similar cases.

4. It is clear that unless all of the conditions of experiment are kept constant, one must analyze all protozoan division rate data in some such manner as that here presented before any conclusions may be drawn as to the existence of "cycles" or "rhythms."
ON THE QUANTA OF LIGHT PRODUCED AND THE MOLECULES OF OXYGEN UTILIZED DURING CYPRIDINA LUMINESCENCE
Authors: Harvey E. Newton
Published: May 2004

A study of the oxygen consumed per lumen of luminescence during oxidation of Cypridina luciferin in presence of luciferase, gives 11.4 x 10–5 gm. oxygen per lumen or 88 molecules per quantum of λ = 0.48µ, the maximum in the Cypridina luminescence spectrum. For reasons given in the text, the actual value is probably somewhat less than this, perhaps of the order of 6.48 x 10–5 gm. per lumen or 50 molecules of oxygen and 100 molecules of luciferin per quantum. It is quite certain that more than 1 molecule per quantum must react.

On the basis of a reaction of the type:

luciferin + 1/2 O2 = oxyluciferin + H2O + 54 Cal.,

it is calculated that the total efficiency of the luminescent process, energy in luminescence/heat of reaction, is about 1 per cent; and that a luciferin solution containing 4 per cent of dried Cypridina material should rise in temperature about 0.001°C. during luminescence, and contain luciferin in approximately 0.00002 molecular concentration.
THE SWELLING OF ISOELECTRIC GELATIN IN WATER
Authors: Northrop John H.
Published: May 2004

The swelling of isoelectric gelatin in water has been found to be in agreement with the following assumptions.

Gelatin consists of a network of insoluble material containing a solution of a more soluble substance. Water therefore enters owing to the osmotic pressure of the soluble material and thereby puts the network under elastic strain. The process continues until the elastic force is equal to the osmotic pressure. If the temperature is raised or the blocks of gelatin remain swollen over a period of time, the network loses its elasticity and more water enters. In large blocks this secondary swelling overlaps the initial process and so no maximum can be observed.

The swelling of small blocks or films of isoelectric gelatin containing from .14 to .4 gm. of dry gelatin per gm. of water is defined by the equation

See PDF for Equation

in which Ke = the bulk modulus

See PDF for Equation.

Ve = gm. water per gm. gelatin at equilibrium; Vf = gm. water per gm. gelatin when the gelatin solidified.
THE EFFECT OF RENNIN UPON CASEIN
Authors: Pertzoff Vladimir
Published: May 2004

1. The preparation and purification of paracasein was described and certain criteria for the absence of free enzyme provided for.

2. The solubility of purified paracasein in water at low temperature was studied, and found practically identical with the solubility of casein.

3. The capacity of paracasein to bind base was investigated by means of its solubility in NaOH at 5° and at 23° ± 2°C., and found to be distinctly different from that of casein.

4. At these two temperature levels paracasein had a 1.5 greater capacity to bind base than casein. The equivalent combining weights of paracasein and casein were found to stand each to the other, apapproximately, as 2 to 3.

5. This relationship suggested that the temperature coefficients of the solubility of paracasein and casein in NaOH are identical.

6. This evidence indicates that paracasein is a modification of casein, distinguishable by physicochemical means.
Proton block of rat brain sodium channels. Evidence for two proton binding sites and multiple occupancy.
Authors: Daumas P , Andersen O S
Published: May 2004

The acid titration function of bilayer-incorporated batrachotoxin (BTX)-modified sodium channels was examined in experiments in which the pH was decreased symmetrically, on both sides of the membrane, or asymmetrically, on only one side. In an attempt to minimize interpretational ambiguities, the experiments were done in 1.0 M NaCl (buffered to the appropriate pH) with channels incorporated into net neutral bilayers. When the pH was decreased symmetrically (from 7.4 to 4.5), the small-signal conductance (g) decreased in accordance with the predictions of a simple (single-site) titration function with a pK of approximately 4.9. As the pH was decreased below 6.5, the single-channel current-voltage (i-V) relation became increasingly rectifying, with the inward current being decreased more than the outward current. When the pH was decreased asymmetrically (with the pH of the other solution being held constant at 7.4), the titration behavior was different for extra- and intracellular acidification. With extracellular acidification, the reduction in g could still be approximated by a simple titration function with a pK of approximately 4.6, and there was a pronounced rectification at pHs < or = 6 (cf. Woodhull, A. M. 1973. Journal of General Physiology. 61:687-708). The voltage dependence of the block could be described by assuming that protons enter the pore and bind to a site with a pK of approximately 4.6 at an apparent electrical distance of approximately 0.1 from the extracellular entrance. With intracellular acidification there was only a slight reduction in g, and the g-pH relation could not be approximated by a simple titration curve, suggesting that protons can bind to several sites. The i-V relations were still rectifying, and the voltage-dependent block could be approximated by assuming that protons enter the pore and bind to a site with a pK of approximately 4.1 at an apparent electrical distance of approximately 0.2 from the intracellular entrance. Based on the difference between the three g-pH relations, we conclude that there are at least two proton binding sites in the pore and that they can be occupied simultaneously.
Ca(2+)-blockable, poorly selective cation channels in the apical membrane of amphibian epithelia. UO2(2+) reveals two channel types.
Authors: Desmedt L , Simaels J , Van Driessche W
Published: May 2004

This study deals with the effect of mucosal UO2(2+) on the Ca(2+)-blockable, poorly selective cation channels in the apical membrane of frog skin and toad urinary bladder. Our data show that UO2(2+) inhibits the Na+ currents through the amiloride-insensitive cation pathway and confirm a previously described stimulatory effect on the amiloride-blockade Na+ transport. Noise analysis of the Ca(2+)-blockable current demonstrates that the divalent also depresses the low-frequency Lorentzian (fc = 11.7 Hz) in the power density spectrum (PDS) and reveals the presence of high-frequency relaxation noise (fc = 58.5 Hz). The action of UO2(2+) is not reversed upon washout and is not accompanied by noise, typically induced by reversible blockers. The divalent merely depresses the plateau of the low-frequency Lorentzian, demonstrating a decrease in the number of conductive cation channels. Similarly, with mucosal K+ and Rb+, UO2(2+) also unmasks the high-frequency Lorentzian by depressing the noise from the slowly fluctuating cation channels (type S). In all experiments with mucosal Cs+, the PDS contains high-frequency relaxation noise (fc = 75.1 Hz in Rana temporaria, and 65.4 Hz in Rana ridibunda). An effect of UO2(2+) on the Cs+ currents and Lorentzian plateaus could not be demonstrated, suggesting that this monovalent cation does not pass through type S channels. Experiments with the urinary bladder revealed only a UO2(2+)-insensitive pathway permeable for Na+, K+, Rb+, and Cs+. We submit that in frog skin two cation-selective channels occur, distinguished by their spontaneous gating kinetics, their sensitivity to UO2(2+), and their permeability for Cs+. In toad urinary bladder, only one kind of cation-selective channel is observed, which resembles the UO2(2+)-insensitive channel in frog skin, with fast open-closed kinetics (type F).
ON THE NATURE OF THE EQUATION FOR GROWTH PROCESSES
Authors: Brown L. A.
Published: May 2004

An analysis of the growth curves of a cladoceran for one adult instar at each of two temperatures is made by comparing the apparent gains or losses in time when the animals are transferred from one of these temperatures to the other during the course of the developmental period. Since the curves for the two temperatures when brought together at their end-point do not coincide, the equation used to describe growth must have at least two velocity constants unequally affected by changes in temperature.
KINETICS OF THE SWELLING OF CELLS AND TISSUES
Authors: Northrop John H.
Published: May 2004

The rate of swelling of Arbacia eggs in dilute sea water, studied by Lillie and by Lucke and McCutcheon, may be expressed by the formulæ derived for the rate of increase in volume of a solution enclosed in a collodion sac.

The rate of swelling of slices of carrot in distilled water, measured by Stiles and Jørgensen, may be expressed by the equation derived previously for the swelling of similarly shaped blocks of gelatin.
THE PRENATAL GROWTH OF THE MOUSE
Authors: MacDowell E. C. , Allen Ezra , MacDowell C. G.
Published: May 2004

1. The general course of prenatal growth in the mouse, the guinea pig, and the chick can be expressed by straight line relations between the logarithms of the weight and age only when age is counted from the beginning of the embryo proper.

2. This is interpreted as showing that the manner of growth before the beginning of the embryo proper is essentially different from that after this time.

3. The velocity constants for the animals mentioned are similar; the major differences in their curves depend on the amount of tissue involved in the first organization of the embryo proper and in the length of prenatal life.

4. Growth of different animals may be compared more accurately if, instead of either birth age or conception age, embryo age is used.
ORIENTATION IN COMPOUND FIELDS OF EXCITATION; PHOTIC ADAPTATION IN PHOTOTROPISM
Authors: Wolf E. , Crozier W. J.
Published: May 2004

During upward geotropic orientation upon a vertical plate the slug Agriolimax creeps vertically, in darkness. Horizontal light from one side produces orientation of dark-adapted slugs away from the vertical path, through an angle (ß). The magnitude of this angle is a function of the light intensity and of time. The moderately rapid course of light adaptation is followed by measurements of ß at fixed intervals. Simple assumptions as to the nature of the orienting forces lead to the conclusion that the logarithm of the tangent of ß should decrease linearly with time, and that the rate of the decrease should vary directly with the logarithm of the light intensity. Both expectations are adequately realized. Certain implications of these results for behavior analysis are pointed out.
ON THE TITRATION OF BACTERIOPHAGE AND THE PARTICULATE HYPOTHESIS
Authors: Clark Harry
Published: May 2004

1. The theory of the serial dilution method of titration of bacterio-phage has been worked out on the basis of the simple particulate hypothesis.

2. It has been shown that, if the dilution constant is .1, only about 60 per cent of parallel runs on the same solution should give the same end-point, the average being taken over a great number of titrations of each of a great variety of solutions.

3. The discrepancy between this figure, 60 per cent, and Dr. Bronfenbrenner's estimate, 85 per cent, is considerable.

4. Inasmuch as the particulate hypothesis is well founded, no explanation of the discrepancy is suggested.
THE EFFECT OF ACETATE BUFFER MIXTURES, ACETIC ACID, AND SODIUM ACETATE, ON THE PROTOPLASM, AS INFLUENCING THE RATE OF PENETRATION OF CRESYL BLUE INTO THE VACUOLE OF NITELLA
Authors: Irwin Marian
Published: May 2004

When living cells of Nitella are exposed to a solution of sodium acetate and are then placed in a solution of brilliant cresyl blue made up with a borate buffer mixture at pH 7.85, a decrease in the rate of penetration of dye is found, without any change in the pH value of the sap. It is assumed that this inhibiting effect is caused by the action of sodium on the protoplasm.

This effect is not manifest if the dye solution is made up with phosphate buffer mixture at pH 7.85. It is assumed that this is due to the presence of a greater concentration of base cations in the phosphate buffer mixture.

In the case of cells previously exposed to solutions of acetic acid the rate of penetration of dye decreases with the lowering of the pH value of the sap. This inhibiting effect is assumed to be due chiefly to the action of acetic acid on the protoplasm, provided the pH value of the external acetic acid is not so low as to involve an inhibiting effect on the protoplasm by hydrogen ions as well. It is assumed that the acetic acid either has a specific effect on the protoplasm or enters as undissociated molecules and by subsequent dissociation lowers the pH value of the protoplasm.

With acetate buffer mixture the inhibiting effect is due to the action of sodium and acetic acid on the protoplasm.

The inhibiting effect of acetic acid and acetate buffer mixture is manifested whether the dye solution is made up with borate or phosphate buffer mixture at pH 7.85. It is assumed that acetic acid in the vacuole serves as a reservoir so that during the experiment the inhibiting effect still persists.
COUNTERACTION OF THE INHIBITING EFFECTS OF VARIOUS SUBSTANCES ON NITELLA
Authors: Irwin Marian
Published: May 2004

When living cells of Nitella are first exposed to (1) phosphate buffer mixture, or (2) phosphoric acid, or (3) hydrochloric acid, or (4) sodium chloride, or (5) sodium borate, and are then placed in a solution of brilliant cresyl blue made up with a borate buffer mixture at pH 7.85, the rate of penetration of the dye into the vacuole is decreased as compared with the rate in the case of cells transferred directly from tap water to the same dye solution.

When cells exposed to any one of these solutions are placed in the dye solution made up with phosphate buffer solution at pH 7.85, the rate of penetration of dye into the vacuole is the same as the rate in the case of cells transferred from the tap water to the same dye solution.

It is probable that this removal of the inhibiting effect is due primarily to the presence of certain concentration of sodium and potassium ions in the phosphate buffer solution. If a sufficient concentration of sodium ions is added to the dye made up with a borate buffer mixture the inhibiting effect is removed just as it is in the case of the dye made up with the phosphate buffer mixture.

The inhibiting effect of some of these substances is found to be removed by the dye containing a sufficient concentration of bivalent cations, or by washing the cells with salts of bivalent cations.

The inhibiting effect and its removal are discussed from a theoretical standpoint.