bluuebunny/crossref_metadata_2025 huggingface dataset:
COLORBLIND VISION
Authors: Hecht Selig , Hsia Yun
Published: May 2004

1. Measurements have been made of the dark-adapted foveal threshold of normal and colorblind persons in five parts of the spectrum using a 1° circular test field.

2. Compared to normals, protanopes (red-blinds) show an elevation of the threshold which increases slowly from blue to yellow and rises rapidly thereafter until in the red the threshold is more than ten times as high as normal. Deuteranopes (green-blinds) do not show so high an elevation, their maximum in the green being only about 70 per cent above normal.

3. These threshold elevations correspond to luminosity losses in the spectrum. For the protanope the total loss in the spectrum is nearly one-half of the normal luminosity; for the deuteranope it is nearly two-fifths of normal.

4. Such losses support the idea that colorblindness corresponds to the loss of one of the three receptor systems usually postulated to account for normal color vision. However, the color sensations reported by colorblind persons, especially monocular colorblinds, do not support the idea of a lost or inactivated receptor system. A fresh explanation for colorblindness is called for to reconcile these conflicting kinds of evidence.
THE OXYGEN CONSUMPTION OF THE MICROSPORES OF TRILLIUM IN RELATION TO THE MITOTIC CYCLE
Authors: Stern Herbert , Kirk Paul L.
Published: May 2004

The oxygen consumption of 265 single Trillium erectum anthers was measured before and during the mitotic cycle of the microspores using a modified differential microrespirometer.

The results show a rising oxygen consumption of the anther in the premitotic stages followed by a sharp drop immediately preceding and during active division. It is suggested from these results that active division may be associated with anaerobic behavior and that the rapid uptake of molecular oxygen commonly associated with proliferating tissues is probably characteristic of premitotic development.
THE QUANTIC AND STATISTICAL BASES OF VISUAL EXCITATION
Authors: Baumgardt Ernest L. M.
Published: May 2004

1. The photochemical theories of vision cannot provide a valid interpretation of the facts over the whole range of brightness. The fact that liminal excitation is increased by the absorption of a very small number of quanta, each absorbing rod receiving a single quantum, excludes the intervention of the mass action law which is the basis of all photochemical theories.

2. Owing to the quantic structure of light and to the random distribution of quanta in a faint light pencil, there must exist numerical relations between the threshold energy on the one hand and the size of the retinal area stimulated and the stimulation time on the other, whatever may be the inner mechanism of liminal excitation. When taking as a basis Van der Velden's experimental results, viz. that two quanta absorbed during a certain interval of time are sufficient to raise threshold excitation, the probability calculus enables us to compute the course of threshold energy in relation to the stimulation time and to the stimulated retinal area. No arbitrary parameter is needed to do so; the only constant to be used is found by experiment.

3. The quantic and statistical theory of visual excitation that we put forward in the present paper enables us to predict the validity of Ricco's law within what we call a "quasi-independent unit" and the validity of Piper's law within a test area made up of a certain number of such units. This theory does not correspond exactly with Piéron's law for foveal threshold in relation to the size of the stimulated area, but the deviation is probably due to an artefact; viz., the action of the micronystagmus.

4. Experiment proves that in region IV of the retina, 15° temporally from the fovea of the right eye of two observers, Ricco's law applies strictly in rod vision from 2'12'' to 31'36'' and, perhaps, further on.

5. In the same region, from 12'30'' to 31'36'', Piper's law applies strictly in cone vision of extremely red light.

6. In peripheral vision with extremely red light the photochromatic interval has been found to be null.

7. Our theoretical interpretation of the term "quasi-independent unit" fits well with the histological data of the retina.

8. Numerical deviations of the theoretic time law of threshold intensity from the empirical course may be due to the existence of a relative refractory period of the ganglion (or bipolar) cells. This mechanism would be a sort of instantaneous adaptation of nervous elements and would explain the fact that the sensation level increases very much slower than the brightness level, in a range of the brightness scale where the photochemical adaptation cannot account for this phenomenon.
VOLUME CHANGES IN HEMOLYTIC SYSTEMS CONTAINING RESORCINOL, TAUROCHOLATE, AND SAPONIN
Authors: Ponder Eric
Published: May 2004

Simultaneous measurement of hemolysis, the volume of the intact cells, and the K lost from the intact cells of systems containing resorcinol, sodium taurocholate, and saponin shows that the volume increases may be conspicuously small while the K losses are large, and that the volume increases are un-equal for equal K losses produced by different lysins. In higher concentrations of the same lysins, the critical volume for hemolysis is a function of the nature of the lysin and of its concentration.

It is impossible to say whether these observations are compatible with the current "dual mechanism" and "colloid osmotic" hypotheses of hemolysis, in which the swelling of the cell is supposed to result from the lysin having made it cation-permeable. The difficulty to be overcome is that the theory cannot be developed to describe volume changes in finite time unless we know what assumptions to make about the mobilities of K and Na, the forces driving them into and out of the cell, etc. The experimental results do not suggest, however, that any simple set of assumptions would be satisfactory.

The conditions which regulate the upper limit of the swelling, i.e. the point at which a swelling phenomenon becomes a hemolytic phenomenon, are functions of the nature of the lysin and sometimes of its concentration. They require to be specified by an independent statement, over and above any statement which may be made about the rate at which swelling occurs in the system. The simplest view of the situation is that the conditions which regulate the critical volume and those which regulate the rate of swelling are both functions, as yet undefined, of the reaction which takes place between the lysin and the structural components of the red cell.
STUDIES IN BIOCHEMICAL GENETICS IN DROSOPHILA
Authors: Villee Claude A.
Published: May 2004

The metabolism of the imaginal discs of wild type, miniature, vestigial, and four-jointed varieties of Drosophila was investigated using the Cartesian diver ultramicrorespirometer. Wild type and vestigial wing disc respiration is inhibited by cyanide and azide and thus is mediated by an iron or copper porphyrin system, presumable cytochrome-cytochrome oxidase. Respiration is also inhibited by certain hydroxynaphthoquinones, believed to inactivate some enzyme between cytochromes b and c. The respiration of the vestigial and miniature wing discs is increased to normal by the addition of ascorbic acid and to a lesser extent by p-phenylenediamine and hydroquinone, hence the cytochrome oxidase and cytochrome c systems of vestigial and miniature wing discs are normal and the effects of these genes are on enzymes below cytochrome c in the respiratory chain.

The respiratory enzymes of the developing imaginal discs of insects are similar to those of a wide variety of cells from bacteria to mammals. The correlation of these biochemical findings with embryological studies of the discs is discussed.
STUDIES ON THE INTERMEDIARY CARBOHYDRATE METABOLISM OF AQUATIC ANIMALS
Authors: DuBois Kenneth P. , Geiling E. M. K. , McBride Arthur F. , Thomson John F.
Published: May 2004

1. Liver, kidney, brain, skeletal muscle, and cardiac muscle from one newborn and three adult long-snouted dolphins (Stenella plagiodon) were obtained for enzyme studies.

2. All of the dolphin tissues exhibited cytochrome oxidase, succinic dehydrogenase, and malic dehydrogenase activity. Considerable differences in the enzyme activities of the various tissues were noted, with cardiac muscle exhibiting the highest respiratory enzyme activity. The enzyme activities of dolphin tissues were lower than those of the corresponding rat tissues.

3. All of the dolphin tissues exhibited adenosine triphosphatase activity which was accelerated by magnesium and manganese but, in contrast to rat tissues, was only slightly activated by calcium.

4. Measurements of the distribution of acid-soluble phosphorus in dolphin tissues indicated that glycolysis in all of the tissues examined proceeded through the Emden-Meyerhof phosphorylation scheme.

5. The average glycogen content of dolphin skeletal muscle was 0.98 per cent as compared with 0.16 to 0.20 per cent for rat skeletal muscle. The high glycogen content of dolphin skeletal muscle indicates a ready source of substrate for glycolysis even during submergence when the blood supply may be differentially shunted to other organs.

6. Measurements of the organ weights of dolphins showed that the lungs occupy over three times and the liver one-half as much of the total body weight as do these organs in the rat. The heart and the thyroid gland of the dolphin are also larger in proportion to the total body weight than in the rat while the relative weights of the other tissues in the two species are about the same.
GALLOXANTHIN, A CAROTENOID FROM THE CHICKEN RETINA
Authors: Wald George
Published: May 2004

A new carotenoid has been isolated from the chicken retina for which the name galloxanthin is proposed. This substance has the properties of a hydroxy carotenoid or xanthophyll. It has not yet been crystallized. On a chromatogram of calcium carbonate it is adsorbed just below astaxanthin and above lutein.

The absorption spectrum of galloxanthin lies in a region where natural carotenoids have not ordinarily been found. Its main, central absorption band falls at about 400 mµ. The position of its spectrum suggests a conjugated system of eight double bonds. This relatively short polyene structure must be reconciled with very strong adsorption affinities.

With antimony trichloride, galloxanthin yields a deep blue product, possessing a main absorption band at 785 to 795 mµ, and a secondary maximum at about 710 mµ which may not be due to galloxanthin itself.

Galloxanthin appears to be one of the carotenoid filter pigments associated with cone vision in the chicken. It may act as an auxiliary to the other filter pigments in differentiating colors; or its primary function may be to exclude violet and near ultraviolet radiations for which the eye has a large chromatic aberration.
OBSERVATIONS ON THE EFFECT OF PENICILLIN ON THE REACTION BETWEEN PHAGE AND STAPHYLOCOCCI
Authors: Krueger A. P. , Cohn T. , Smith P. N. , McGuire C. D.
Published: May 2004

The essential facts relating to the reaction between phage, sodium penicillin G, and the K race of Staphylococcus aureus are:

1. Except when [P] is very high, massive lysis of the cellular substrate occurs considerably sooner in the P-PN-B mixture than in preparations containing P alone or PN alone.

2. The accelerative effect is present in concentrations of PN varying from 0.1 to 1 x 104 units/ml.

3. Acceleration of lysis can be secured by exposing staphylococci to PN prior to treatment with P.

4. In certain concentrations of P and B in tryptose-phosphate broth, P formation apparently takes place without bacterial reproduction. The extent to which P is produced is influenced very little by [PN]0 but is markedly dependent upon [P]0. With low P/B ratios the [P] curve shows a lag followed by a rapid rise to a peak of 25 to 30 times [P]0. When the P/B ratio approaches unity there is a considerable primary drop in [P] and later an increase which, however, fails to bring the total P produced above [P]0. When P/B is still higher, the [P] curve drops profoundly as the bacteria lyse and never enters into a productive phase.

5. In Locke's solution mixtures of P-PN-B, containing 5 to 10 per cent broth, P formation occurs in the absence of detectable cellular reproduction to the extent of a four- to sixfold increase over [P]0.

6. Direct microscopic examination of wet preparations removed during the P-PN-B reaction has disclosed swelling of the staphylococci. The swollen cells are three times the diameter of normal S. aureus secured from an 18 hour culture. Cellular swelling apparently accounts for the experimental observation that the curve for lysis plotted from [B]K lags considerably behind the [B]D curve. Increase in the size of individual cells would tend to keep the photoelectric colorimeter measurements high even while the direct count was diminishing.

7. When the P-PN-B reaction is carried out in broth, attainment of the peak in P production is followed by a moderate loss of P. This does not occur when P, PN, and B react in Locke's solution.

The reaction dealt with here between P, PN, and S. aureus is similar in a good many respects to that investigated by Price for P, PN, and S. muscae. For example, in both cases P is produced without bacterial reproduction. There are, however, certain noteworthy differences: (a) PN increases the time of half-lysis for S. muscae and lessens it for S. aureus. (b) The yields of P in ranges of [P] and [PN] permitting P formation without bacterial reproduction are higher for S. muscae than for S. aureus. (c) An increase in [PN] from 33 units/ml, to 833 units/ml, greatly reduces the final plaque count secured with S. muscae as a substrate but has no discernible influence on the reaction when S. aureus is used.

Currently studies are in progress on the P-PN-B reaction in a synthetic medium in order to obtain information on the mechanism involved.
PROTEOLYTIC CONTAMINANTS OF CRYSTALLINE RIBONUCLEASE
Authors: McDonald Margaret R.
Published: May 2004

1. The ability of crystalline ribonuclease to hydrolyze proteins is due to impurities present in the preparations and not to an intrinsic property of the ribonuclease molecule. The amounts of these impurities vary enormously with different preparations.

2. The dangers inherent in the use of crystalline enzymes as specific tools, without assaying them for all possible interfering impurities, are emphasized.
THE PERMEABILITY OF HUMAN RED CELLS TO CATIONS AFTER TREATMENT WITH RESORCINOL, n-BUTYL ALCOHOL, AND SIMILAR LYSINS
Authors: Ponder Eric
Published: May 2004

The form of families of curves relating K loss to time in systems containing hypolytic concentrations of resorcinol and of n-butyl alcohol points to the human red cell's being slightly permeable to K and Na even when it is in isotonic NaCl (or plasma), and to the effect of the hypolytic concentrations of lysin being such as to increase this permeability.

The rate of reentry of K into red cells which have lost it is more rapid than the rate of the previous loss. This may be due to the reimmersion of the lysin-treated cells in isotonic KCl producing further modifications of the ion-restricting mechanisms associated with the red cell structure.

The volume changes observed in systems which show the large K-Na exchanges produced by resorcinol and by n-butyl alcohol are not the same as those which would be expected on the basis of the dual mechanism of hemolysis hypothesis or of the colloid-osmotic hemolysis hypothesis. Extensive swelling of the red cells occurs only when the concentrations of lysin are large enough to produce considerable hemolysis.
THE STIMULATING EFFECT OF GLYCOLS AND THEIR POLYMERS ON THE TARSAL RECEPTORS OF BLOWFLIES
Authors: Dethier V. G. , Chadwick L. E.
Published: May 2004

The rejection thresholds of Phormia regina Meigen for twenty-four glycols have been determined. A definite relationship between the concentration of the test material and the distribution of thresholds has been noted regularly in samples of flies selected at random from a population of known age which had been reared under standard conditions. The scattering of thresholds is normal with respect to the logarithm of concentration. Recalculation of the data of other workers reveals the same sort of relationship with other species of insects and the minnow Phoxinus. The underlying reason for the phenomenon is not known.

The glycols in common with other series of homologous alipbatic compounds are rejected at logarithmically decreasing concentrations as the chain length is increased. In general the straight chain diols are more stimulating than the corresponding polyethylene and polypropylene glycols. This difference is related in some manner to the presence of ether linkages in the latter. Polypropylene glycols, with chains of three carbon atoms between the ether linkages are more stimulating than polyethylene glycols, where the spacing is —O—C—C—O—. Unipolymers are more stimulating than mixtures of homologues with the same average molecular weights. Polyethylene glycol 1540 is the largest molecule of measured molecular weight known to stimulate chemoreceptors. The introduction of a second terminal hydroxyl group into the straight hydrocarbon chain reduces the stimulating effect. Alcohols corresponding to the first three diols average about four times as stimulating as the latter while those corresponding to the higher diols average more than one hundred times as stimulating.
PHYSICAL STRUCTURE OF SHELL MEMBRANES
Authors: Wolken J. J. , Schwertz F. A.
Published: May 2004

The results obtained in the present work bring out clearly that the dried shell membrane is an open lattice-like network containing micropores of the order of 1 micron in mean equivalent diameter and whose surface density is roughly 20 millions per sq. cm. The gas transfer through this network is largely by viscous flow and accordingly does not obey Graham's law of diffusion.

The data make clear that dried shell membranes are extremely permeable to all the gases examined and that wet membranes are completely impermeable. This fact leads one to suspect that during embryonic development, the rate of influx of gases is controlled in some measure by the moisture content of the shell membrane.

The permeability technique developed here should be of value in the study of other membranes and especially natural membranes of biological importance.
REGULATORY MECHANISMS OF CELLULAR RESPIRATION
Authors: Barron E. S. Guzman , Muntz John A. , Gasvoda Betty
Published: May 2004

Uranium as UO2(NO3)2 combines reversibly with proteins. The degree of dissociation of this combination depends, among other factors, on the H+ concentration. At pH 7.3 the U-albumin complex was easily dissociated on addition of citrate, while at pH 3.8 it was not. Uranium inhibited reversibly a number of enzyme systems.

Uranium enzyme inhibitions could be reversed on addition of certain hydroxypolycarboxylic acids (citric acid, α-hydroxyaspartic acid, malic acid); in no case, however, did phosphate have any effect.

In cell-free yeast juice, the fermentation of glucose-hexosediphosphate was inhibited by UO2(NO3)2. Slight reactivation occurred on addition of phosphate.

In living yeast cells, the fermentation and oxidation of glucose was inhibited by small amounts of UO2(NO3)2 (7,7 micrograms per mg. dry weight), while the oxidation of acetic acid, ethyl alcohol, malic and citric acids, was not affected at all. U inhibition in living yeast cells at pH 7.3 was completely released on addition of small amounts of phosphate, adenosinetriphosphate, and citrate, while at pH 3.8 U inhibition was not released by phosphate and citrate. At saturation, one yeast cell contained 7.06 x 106 molecules of uranium. Lactic dehydrogenase was not inhibited by U while the oxidation of lactic acid by gonococci was inhibited. Addition of phosphate released this inhibition. The U inhibition of liver succinoxidase was unaffected by phosphate, while the U inhibition of the oxidation of succinate by E. coli was released by phosphate.

It has been concluded from these experiments that U inhibition of cell metabolism is due to combination of the metal with the protein portion of the cell membrane. Uranium is presented as an example of surface inhibition.
PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES
Authors: Price Winston H.
Published: May 2004

1. The release of S. muscae phage in veal infusion medium is correlated with lysis of the host.

2. The release of the bacterial virus in Fildes' synthetic medium occurs in a step-wise manner before observable lysis of the cells occurs. This result has been confirmed by both turbidimetric readings and direct microscopic examination of the infected cells.
TEMPERATURE ACTIVATION OF CERTAIN RESPIRATORY ENZYMES OF STENOTHERMOPHILIC BACTERIA
Authors: Gaughran Eugene R. L.
Published: May 2004

The results of this study of the effect of temperature on the respiratory mechanism of five stenothermophilic bacteria may be summarized as follows:—

1. The respiratory mechanism and its various components of the stenothermophilic bacteria were found to function at temperatures below the minimum temperature for growth of these organisms. In every case the rates of the individual reactions involved in the respiratory chain increased exponentially with temperature until the temperature at which inactivation became apparent was reached.

2. The mean activation energies, calculated from the "best" value for the slope of the straight lines resulting from a plot of log rate against the reciprocal of the absolute temperature were:

Dehydrogenases: 28,000 to 28,500 calories per gram molecule. Glucose, fructose, galactose, mannose, xylose, arabinose, maltose, lactose, sucrose, glycine, ß-alanine, monosodium glutamate, (asparagine).

19,500 to 20,500 calories per gram molecule. Ethyl alcohol, succinate, pyruvate, lactate, acetate.

19,500 to 20,500 calories per gram molecule. Ethyl alcohol, succinate, pyruvate, lactate, acetate.

15,000 calories per gram molecule. Formate.

Cytochrome oxidase and cytochrome b and c (substrate: p-phenylenediamine): 16,800 calories per gram molecule.

Cytochrome oxidase and cytochrome c (substrate: hydroquinone): 20,200 calories per gram molecule.

Catalase: 4,100 calories per gram molecule.

Complete aerobic respiratory system (plus added glucose): 29,500 calories per gram molecule.

3. The identity of the energies of activation of the respiratory system and its enzymic components at temperatures above and below the minimum temperature for growth of the stenothermophilic bacteria was demonstrated.

4. An attempt has been made to indicate a relationship between the nature of the substrate and the activation energy by grouping substrates on the basis of common µ values obtained for their dehydrogenation by resting cell preparations of stenothermophilic bacteria. The dehydrogenation reactions have been found to be the rate-controlling reactions in the aerobic respiratory system of these bacteria.
AQUEOUS HUMOR/PLASMA CHLORIDE RATIOS IN RABBITS, DOGS, AND HUMAN BEINGS
Authors: Kinsey V. Everett
Published: May 2004

The ratio of concentration of chloride in the aqueous humor compared with that in the plasma of rabbits, dogs, and human beings, was determined by the Schales and Sendroy methods. Consistent results were obtained in all the experiments by the Schales method with or without protein, and by the Sendroy method without protein. In the presence of protein, however, lower chloride concentrations were found in the plasma of dogs and human beings by the Sendroy method. The ratios in this instance were higher than values predicted on the basis of Gibbs-Donnan equilibrium and similar to those obtained by several previous investigators using the same method. With rabbits both methods gave essentially the same results under all conditions.

The ratios (Schales and Sendroy) for the rabbits based on arterial plasma averaged 0.98, on venous plasma 1.00; the ratio (Schales) for the dog for venous plasma was 1.00; the ratio (Schales, protein present or removed; Sendroy, protein removed) for human beings, based on venous plasma, was approximately 1.03. Ratios of 1.08 for the dog and 1.07 for human beings were obtained by the Sendroy method in the presence of protein. Possible explanations for these apparent discrepancies are discussed. In dogs and in human beings, the major evidence supports the contention that the aqueous humor/plasma chloride ratio is not in excess of that predicted by the Gibbs-Donnan equilibrium and therefore requires no special explanation. In the rabbit all the evidence indicates that the chloride ratios are actually less than the value predicted by the Gibbs-Donnan equilibrium.
STIMULATION OF TARSAL RECEPTORS OF THE BLOWFLY BY ALIPHATIC ALDEHYDES AND KETONES
Authors: Chadwick L. E. , Dethier V. G.
Published: May 2004

Rejection of eight aldehydes, eight ketones, five secondary alcohols, and 3-pentanol has been studied in the blowfly Phormia regina Meigen. The data agree with results previously reported for normal alcohols and several series of glycols in showing a logarithmic increase in stimulating effect with increasing chain length. The order of increasing effectiveness among the different species of compounds thus far investigated is the following: polyglycols, diols, secondary alcohols, iso-alcohols, normal alcohols, ketones, iso-aldehydes, normal aldehydes.

Curves relating the logarithms of threshold concentration to the logarithms of chain length for diols, alcohols, aldehydes, and ketones show inflections in the 3 to 6 carbon range. Above and below the region of inflection the curves are nearly rectilinear. The slopes for the upper limbs (smaller molecules) are of the order of –2; for the lower limbs, about –10.

Comparisons of the threshold data with numerical values for molecular weights, molecular areas and volumes, oil-water distribution coefficients, activity coefficients, standard free energies, vapor pressures, boiling points, melting points, dipole moments, dielectric constants, and degree of association are discussed briefly, and it is concluded that none of the comparisons serves to bring the data from the several series and from the two portions of each series into a single homogeneous system. A qualitative comparison with water solubilities shows fewer discrepancies.

It is suggested that the existence of a combination of aqueous and lipoid phases at the receptor surface would fit best with what is presently known about the relationship between chemical structure and stimulating effect in contact chemoreception. In this hypothesis the smaller and more highly water-soluble compounds are envisaged as gaining access to the receptors partly through the aqueous phase, the larger molecules predominantly through the lipoid phase.
THE RATE OF LOSS OF POTASSIUM FROM HUMAN RED CELLS IN SYSTEMS TO WHICH LYSINS HAVE NOT BEEN ADDED
Authors: Ponder Eric
Published: May 2004

Curves describing the loss of K from human red cells as a function of time can be interpreted in terms of an equation which treats the K content of the cell (φ) as the result of an accumulation process occurring at a rate P and an outward diffusion process regulated by a constant a. The equation is useful for describing the observations and for exploring the mechanisms which may be responsible for the K losses, although it cannot be used for analyzing the experimental data in a strict sense in the absence of independent metabolic data because P and a may both be functions of time. The applicability of the equation is illustrated by its use in connection with experimental curves showing K loss as a function of time at 4°, 25°, and 37°C. for systems containing human red cells in isotonic NaCl or NaCl-buffer.

At 4°C., the K loss follows an exponential curve approaching an asymptote in the neighborhood of φ = 0.50 ± 0.15. The corresponding value of P implies that the cells are able to accumulate about 0.6 per cent of their initial K per hour under these conditions.

At 25°C., the K loss starts exponentially but becomes roughly linear with time after 24 to 48 hours. The change of form is probably due to the appearance of autolysins in the system. Curves of a similar mixed or intermediate form may be obtained even at 4°C. if the observations are sufficiently extended and if spontaneous hemolysis becomes appreciable.

At 37°C., the K loss is exponential for the first 24 to 36 hours, the curves approaching asymptotes which, translated into terms of P, indicate that the cells can accumulate about 7 ± 3 per cent of their initial K per hour. After this time autolysis begins to affect the shape of the curves, the rate of K loss increasing rapidly.

The effect of adding fluoride or iodoacetate is to lower the position of the asymptote to which the curves proceed; i.e., to decrease the accumulation rate P, to increase the diffusion constant a, or both. Cyanide has almost no effect. Hypotonicity has little effect on the rate of K loss at 37°C.; at 4°C., the rate of loss is somewhat less in hypotonic NaCl.

The observation that the K loss in systems at 4°C. and containing as much as 0.086 M NaF does not become complete, but proceeds exponentially towards an asymptote between φ = 0.2 and 0.4, suggests that 20 to 40 per cent of the cell K is much less diffusible than the remainder at low temperatures and in the absence of lytic substances. A similar conclusion is suggested by the form of the curve for K loss into saline at 4°C., an accumulation rate of 0.6 m. eq./litre of cells/hour at the end of 100 hours or more being improbably great for a system at such a low temperature and containing no added glucose.
PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES
Authors: Price Winston H.
Published: May 2004

1. In the synthetic medium of Fildes contaming hydrolyzed casein virus release is not correlated with observable cellular lysis under conditions of a very low multiple infection.

2. In cells with a high multiple infection, lysis occurs much sooner than in cells with a low multiple infection and virus release is correlated with cellular lysis. The experiments indicate that it is the virus particle itself which accelerates lysis under these conditions.

3. A non-dialyzable fraction has been isolated from yeast, the addition of which results in cellular lysis occurring at a sooner than usual interval and being correlated with virus release in cells having a very low multiple infection.

4. By varying the concentration of the yeast fraction, it is possible to lyse the cells at varying times under conditions of a low multiple infection.
THE STATE OF THE CHROMOSOMES IN THE INTERPHASE NUCLEUS
Authors: Ris Hans , Mirsky A. E.
Published: May 2004

In the living interphase nucleus no chromosomal structures are visible. Yet in the injured cell and after treatment with most histological fixatives chromatin structures become apparent. Under certain conditions this appearance of structure in the living interphase nucleus is reversible.

We have found that this change in the interphase nucleus is the result of a change in the state of the chromosomes. In the living nucleus the chromosomes are in a greatly extended state, filling the entire nucleus. Upon injury the chromosomes condense and therefore become visible. At the same time the nuclear volume decreases. This behavior of the chromosomes is connected with their content of desoxyribonucleic acid (DNA). This view is based on the following observations:

(a) Distribution of DNA in the Nucleus.—(1) The living interphase nucleus of uninjured cells absorbs diffusely at 2537 Å. No chromosomal structures are visible in ultraviolet photographs unless they are also distinct in ordinary light. If the chromosomes are made to condense they become visible and the absorption at 2537 Å is now localized in these structures. (2) After fixation with formalin and osmic acid interphase nuclei stain diffusely with Feulgen. These fixatives preserve the extended state of the chromosomes. (3) If nuclei are teased out in non-electrolytes (sucrose, glycerin) the chromosomes are extended. Such nuclei stain homogeneously with methyl green. On adding salts the chromosomes condense and the methyl green is now restricted to the visible structures.

(b) Extension and Condensation of Isolated Chromosomes.—When chromosomes isolated from interphase nuclei of calf thymus are suspended in sucrose, their volume is four to five times larger than in saline, but they retain their characteristic shapes. Chromosomes from which DNA and histone have been removed do not show this reversible extension and condensation, neither do lampbrush chromosomes of frog oocytes which contain very little DNA.

During mitosis a partial condensation of the DNA occurs in prophase, so that the mitotic chromosomes now occupy a much smaller volume of the nucleus. At telophase the chromosomes swell again to fill the entire nucleus.
THE EFFECT OF TEMPERATURE ON POTASSIUM EQUILIBRIA IN CHICK EMBRYO MUSCLE
Authors: Wesson Laurence G. , Cohn Waldo E. , Brues Austin M.
Published: May 2004

The effect of temperature upon the exchange rates between intra- and extracellular potassium in chick embryo muscle was determined by the use of radioactive potassium. The temperature coefficient of at least four-fifths of the cell potassium is large. At temperatures below 15°C., potassium is lost from the cell and is regained on warming. The results suggest the possibility that 20 per cent or less of the cell potassium may differ from the rest by being more rapidly exchangeable with the medium.
MOVEMENTS OF WATER IN CELLS OF NITELLA
Authors: Osterhout W. J. V.
Published: May 2004

When one end of a Nitella cell (A) is bathed in water and a solution of sucrose is placed at the other (B) we find that water enters at A, travels along inside the cell, and escapes at B. The solutes which cannot pass out through the protoplasm at B remain behind so that the osmotic pressure increases at B and diminishes at A until equilibrium is reached and the motion stops.

An equation is given which enables us to predict with considerable accuracy the amount of flow required to produce equilibrium.
MUTANTS PRODUCED BY X-IRRADIATION OF SPORES OF CHAETOMIUM GLOBOSUM AND A COMPARISON WITH THOSE PRODUCED BY ULTRAVIOLET IRRADIATION
Authors: Ford J. M. , Kirwan D. P.
Published: May 2004

1. Mutants produced by x-irradiation of fungal spores of Chaetomium globosum have been compared with those produced by ultraviolet irradiation.

2. The most striking difference between the mutants produced by x-irradiation and ultraviolet irradiation is the absence in x-ray experiments of the K mutant which is produced in large numbers at short ultraviolet wave lengths.

3. A comparison is made of the relation between x-ray dose and numbers of lethal mutants, and the relation between the short ultraviolet wave length 2804 dose and numbers of lethal mutants. Both are compared with theoretical curves for 1, 2, 5, and 8 quantum hits.

4. The production of lethal mutants by x-rays is shown to be consistent with the theoretical curve for five quantum hits on the sensitive spot of the spore, whereas the production of lethal mutants by the ultraviolet wave length 2804 Å.u. is consistent with two quantum hits.
THE INFLUENCE OF HYDROSTATIC PRESSURE AND URETHANE ON THE THERMAL INACTIVATION OF BACTERIOPHAGE
Authors: Foster Ruth A. C. , Johnson Frank H. , Miller Virginia K.
Published: May 2004

In Difco nutrient broth, containing 0.5 per cent NaCl, pH 6.6, Escherichia coli phages T1, T2, and T5 were inactivated at 66°C., and T7 at 60°C., at nearly the same rate. In each case the rate of destruction was not uniform but more or less decreased with time of heating. With T2 there was an initial increase in number of infective centers after heating for several minutes at 66°C.

Hydrostatic pressures up to 10,000 pounds per square inch retarded the thermal destruction of T1, T2, and T5, but accelerated that of T7, while small concentrations of urethane accelerated the rate of each.

The rate of inactivation was increased by the addition of 0.005 M phosphate, and was decreased by 0.005 M MgCl2 in all but T7, whose rate was unaffected by this amount of Mg. The influence of Ca was similar to that of Mg.

The addition of 0.005 M MgCl2 to the broth medium resulted in a first order rate of destruction of T5 at either normal or increased pressure, and with as well as without urethane. Analysis of data obtained under these conditions indicated that the thermal inactivation proceeds with a volume increase of activation of 113 cc. per mol, and with a heat and entropy of 170,000 calories and 425 E. U., respectively, in the rate-limiting reaction. In the presence of 0.1 M urethane the heat and volume change of activation are apparently slightly greater. The relation between concentration of urethane and the amount of acceleration in rate of destruction at normal pressure and 66°C. indicated that the total rate involves at least two first order rate processes: the thermal inactivation itself and a urethane-catalyzed reaction, the latter involving the combination of an average of 2.3 molecules of urethane in the activated state of the bacteriophage molecule whose destruction results in loss of phage activity.
ELECTRICAL PHENOMENA IN NERVE
Authors: Shanes Abraham M.
Published: May 2004

The action of a number of agents, which may be classified as "stabilizers" and "unstabilizers" on the electrical oscillations and after-potentials in the squid giant axon has been examined. The effects on the spike, "positive overshoot," and "potassium potential" were also observed, but where possible concentrations were employed which left these phenomena unaltered.

Veratrine augmented the oscillations and the negative after-potential, particularly with repetitive stimulation. Yohimbine caused a small long lasting positive after-potential and depressed the oscillations, effects also enhanced with repetitive activity. Cocaine and procaine suppressed the oscillations and the negative after-potential but DDT was completely inert. An elevation in the medium calcium depressed the oscillations and the naturally occurring negative after-potential; negative after-potentials induced with veratrine were increased by calcium. A decrease in the potassium augmented the oscillations and the negative after-potential.

A hypothesis is presented in which these effects are interpreted in terms of potassium concentration at the fiber surface as regulated by a labile permeability and metabolism. This is discussed in relation to the available evidence for these factors.

It is a pleasure to acknowledge the author's indebtedness to Dr. D. E. S. Brown, Director, and to his staff at the Bermuda Biological Station for Research for the cooperation and special facilities provided during the initiation of this work. Dr. T. Baylor of Princeton University very kindly provided the camera and film used in Bermuda.
ELECTRICAL PHENOMENA IN NERVE
Authors: Shanes Abraham M.
Published: May 2004

The resting and action potentials of the leg nerves of the spider crab are reduced by procaine, cocaine, iodoacetate, KCl, and veratrine. The first three agents depress the sensitivity of the resting potential to anoxia, while the last can be shown to augment it. Glucose sustains activity and the polarized state in the absence of oxygen, an effect blocked by iodoacetate; corresponding concentrations of lactate and pyruvate are inert under most experimental conditions. DDT and veratrine both induce repetitive activity following an impulse, but only the latter does so with a marked increase in negative after-potential.

The negative after-potential induced by veratrine is decreased by KCl relatively more than the spike or the resting potential. Elevation of the calcium content of the medium increases this after-potential. Neither ion appreciably alters the time constant of repolarization. The recovery is more rapid than that obtained following prolonged activity of both veratrinized and unveratrinized nerves. Repolarization following a tetanus is accelerated by an increase in the volume of solution in contact with the fibers; associated with this is an augmentation of the positive after-potential which normally follows a bout of activity. Yohimbine induces a positive after-potential following individual spikes which is depressed by an elevation of the potassium or calcium content of the medium.

These observations are discussed from the standpoint of the available evidence for the involvement of potassium at the surface of the fibers as regulated by a labile permeability and metabolism. The potassium liberated by the action potential, calculated from the polarization changes, agrees closely with an available analytical figure; less direct observations are also found to be consistent with this view.
ON THE MUTATION OF THE TOBACCO MOSAIC VIRUS
Authors: Opatowski I.
Published: May 2004

Experiments on x-ray-induced mutations of the tobacco mosaic virus (Gowen) are analyzed on the basis of the ionization theory. The size of the volume within which the primary process of mutation develops is calculated on the basis of three alternative assumptions; viz., (1) that this volume consists of protein, (2) that it is nucleic acid, (3) that it is phosphorus. It is found that the volume calculated under assumption (1) is identical with the hexagonal cell unit which Bernal and Fankuchen found in the virus protein by x-ray diffraction. Assumptions 2 and 3 lead respectively to the conclusions that one-fourth of the total nucleic acid content or one-half of the total phosphorus content is involved in the mutational process. The relation between the induced and the spontaneous mutation is examined and it is found that natural ionizing radiations are completely insignificant for the spontaneous mutation of the virus.
TONICITY-VOLUME RELATIONS IN PARTIALLY HEMOLYZED HYPOTONIC SYSTEMS
Authors: Ponder Eric
Published: May 2004

The linear relation between the red cell volume V and the reciprocal of the tonicity T of a hypotonic medium is not the linear one expected on the basis of the van't Hoff-Mariotte law, particularly when a fraction p of the cells are hemolyzed and the volume V/(1 – p) of the (1 – p) cells which remain intact is considered. In systems of relatively high tonicity in which p is zero, the relation is linear but its slope is usually too small; at lower tonicities in which p has a value between zero and 0.35, the volumes are larger than those expected on the basis of the van't Hoff-Mariotte law, while at still smaller tonicities they are much smaller than expected. The volume measurements referred to are made with a high speed hematocrit; the results obtained in systems containing relatively high and relatively low volume concentrations of cells are contrasted with each other, and allowance is made in the calculations for the volume of the hypotonic medium surrounding the cells being limited.

Attempts are made at an explanation of the anomalous results in terms of incomplete packing, of a stepwise as opposed to an all-or-none loss of Hb from the cells, of a heterogeneity in the swelling properties of the cells of the population, of a loss of osmotically active substances from the intact cells, and of the red cell ghost having some degree of rigidity. These explanations are not satisfying, although some of them in combination may account for the phenomena observed. It seems likely that the structures involved in the hemolytic process (cells and ghosts) have different properties in different tonicity ranges and even when the same tonicity is established in systems which are dense, as opposed to dilute, with respect to cell concentration.

The form of the tonicity-volume relation can be changed substantially, although not in the direction of greater linearity, by treating the cells with resorcinol, colloidal silicic acid, iodoacetate, or sodium oxalate. Small changes in pH, exposure to temperatures as high as 37°C., allowing the cells to stand for periods up to 24 hours, or the substitution of hypotonic plasma for hypotonic NaCl-buffer, produce, on the other hand, only minor changes in the tonicity-volume relation.
THE LOSS OF POTASSIUM FROM FROG NERVES IN ANOXIA AND OTHER CONDITIONS
Authors: Fenn Wallace O. , Gerschman Rebeca
Published: May 2004

1. Frog nerves immersed in Ringer's solution lose on the average 23 per cent more potassium if the solution is equilibrated with pure nitrogen than if equilibrated with oxygen.

2. Tying off the ends of the nerves during immersion increased rather than diminished the loss of potassium.

3. There was some evidence that nerves tended to regain potassium if they were returned to oxygen after a period of anoxia.

4. Addition of acetylcholine to the solution increases the loss of potassium.

5. Equilibration of the solution and nerves with 20 per cent CO2 in O2 increases the loss of K from nerves in Ringer's solution but decreases it in frog blood.
THE ULTRAVIOLET LIGHT AND PHOTOSENSITIZED INACTIVATION OF TOBACCO MOSAIC VIRUS
Authors: Oster Gerald , McLaren A. Douglas
Published: May 2004

The quantum yield for the inactivation of tobacco mosaic virus has been determined at 253.7 mµ and found to be 4.3 x 10–6. The possible significance of the observed one-hit process of inactivation has been discussed in terms of the kinetics and the rupture of model substances including nucleic acid. The ultraviolet light inactivation, which proceeds independent of oxygen, occurs without change in physicochemical properties, with the possible exception of an enhanced sensitivity to thermal denaturation.

The photosensitized inactivation of virus by acriflavine has been found to proceed parallel with the destruction of the dye. The action was found to be dependent upon adsorbed dye, and the inactivation is enhanced by the presence of oxygen.
STUDIES ON THE MECHANISM OF ACTION OF IONIZING RADIATIONS
Authors: Barron E. S. Guzman , Flood Veronica
Published: May 2004

Thiol compounds, such as glutathione, 2,3-dimercaptopropanol (BAL), propane-1,3-dithiol, and N-phenylaminopropanedithiol, were readily oxidized by x-rays, beta rays, and gamma rays. The ionic yield for this oxidation was about the same, 3 at pH 7, on irradiation with x-rays and with beta rays; it was 23 per cent less on irradiation with gamma rays. The ionic yield varied with the hydrogen ion concentration, increasing as the pH value increased. There was no reduction of oxidized glutathione on irradiation with dosages of x-rays and gamma rays which produced oxidation of the reduced compound. In the absence of oxygen, the oxidation of thiols by ionizing radiations was only 33 per cent of that obtained in the presence of dissolved oxygen. When the thiol solutions were irradiated in the presence of dissolved oxygen, catalase protected them from oxidation by 17 to 27 per cent.
DELAY OF CLEAVAGE OF THE ARBACIA EGG BY ULTRAVIOLET RADIATION
Authors: Blum Harold F. , Price Judith P.
Published: May 2004

While our data do not permit us to state the exact locus or mode of action of ultraviolet radiation in the Arbacia egg, certain general conclusions may be reached. The amount of delay of cleavage of these eggs is determined by two principal factors: (1) The extent of an effect, resulting from photochemical action induced by ultraviolet radiation, which is reversible in a biological sense, the reversibility not being directly dependent upon the process of cell division. (2) The sensitivity of the cell division process to the effects of the ultraviolet-induced photochemical reaction. This factor varies with the stage of cell division, the cell being insensitive during a period corresponding to most of mitosis.

It seems likely that these findings may apply to cell division in general, but, since the quantitative relationships observed must, in this case, reflect the integration of two semi-independent factors, the over-all picture may appear quite different for different kinds of cells.