bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE ACCUMULATION OF ELECTROLYTES
Authors: Osterhout W. J. V. 
Published: May 2004

It is suggested that K enters chiefly as KOH, whose thermodynamic potential (proportional to the ionic activity product (aK) (aOH)) is greater outside than within. As this difference is maintained by the production of acid in the cell K continues to enter, and reaches a greater concentration inside than outside. KOH combines with a weak organic acid which is exchanged for HCl entering from the sea water (or its anion is exchanged for Cl-), so that KCl accumulates in the sap.
Na enters more slowly and its internal concentration remains below that of K.
The facts indicate that penetration is chiefly in molecular form.
As the system is not in equilibrium the suggestion is not susceptible of thermodynamic proof but it is useful in predicting the behavior of K, Na, and NH4.
THE ACCUMULATION OF ELECTROLYTES
Authors: Jacques A. G. , Osterhout W. J. V. 
Published: May 2004

When 0.001 M NH4Cl is added to sea water containing Valonia macrophysa there seems to be a rapid penetration of undissociated NH3 (or NH4OH) which raises the pH value of the sap so that the thermodynamic potential of KOH becomes greater inside than outside and in consequence K leaves the cell: NaOH continues to go in because its thermodynamic potential is greater outside than inside.
NH4Cl accumulates, reaching a much higher concentration inside than outside. This might be explained on the ground that NH3, after entering, combines with a weak organic acid produced in the cell whose anion is exchanged for the Cl- of the sea water, or (more probably) the organic acid is exchanged for HCl.
THE ORDER OF DEATH OF ORGANISMS LARGER THAN BACTERIA
Authors: Rahn Otto 
Published: May 2004

In a previous paper it has been shown that the logarithmic order of death of bacteria can be accounted for by the assumption of some very unstable molecules so essential for reproduction that the inactivation of only one such molecule per cell prevents reproduction and makes the cell appear "dead" according to the standard method of counting living bacteria.
In the present paper dealing with the order of death of larger organisms, only a motile alga, Chlamydomonas, is shown to have the same order of death.
The very scant material on the order of death of yeasts is contradictory. It seems possible that more than one molecule must be destroyed to kill a yeast cell.
With the spores of a mold, Botrytis cinerea, the number of "reacting molecules" is decidedly larger than 1.
A flagellate, Colpidium, gave a survivor curve suggesting the destruction of two molecules before motility ceases. Erythrocytes exposed to ultra-violet light also follow the formula for two reacting molecules.
The analysis of the survivor curves of multicellular organisms is not possible because no distinction between the number of essential molecules and the number of essential cells seems possible. Besides, variability of resistance changes the shape of the survivor curves in such a way that it becomes impossible to differentiate between variability and actual survivor curve.
The general results seem to justify the assumption that in each cell, the number of molecules which are really essential for life and reproduction, is quite limited, and that, therefore, equal cells will not react simultaneously, though ultimately the reaction will be the same.
This theory of lack of continuity in cell reactions owing to the limited number of reacting molecules is an analogon to the quantum theory where continuity ceases because division of matter reaches a limit.
It seems probable that this lack of continuity in cell reactions has a general biological significance reaching beyond the order of death.
A METHOD FOR DETERMINING THE OXYGEN CONSUMPTION OF A SINGLE CELL
Authors: Howland Ruth B. , Bernstein Alan 
Published: May 2004

1. A method for measuring the O2 consumption of a single cell is described. The cell is placed in a capillary tube adjacent to a bubble of air. KOH (5 per cent) is drawn in on the opposite side of the air and both ends of the tube are sealed with mineral oil. The decrease in the volume of the gas, representing the O2 consumed, is followed.
2. The possible errors of the technique are appraised.
3. A single Actinosphaerium eichhornii consumes 0.00113 mm.3 of O2 per hour. A single Paramecium caudatum consumes 0.00049 mm.3 of O2 per hour.
4. The significance of the results and the limitations of the method are discussed.
FURTHER STUDIES ON THE KINETICS OF OSMOSIS IN LIVING CELLS
Authors: Lucké Balduin , Hartline H. Keffer , McCutcheon Morton 
Published: May 2004

Using unfertilized eggs of Arbacia punctulata as natural osmometers an attempt has been made to account for the course of swelling and shrinking of these cells in anisotonic solutions by means of the laws governing osmosis and diffusion. The method employed has been to compute permeability of the cell to water, as measured by the rate of volume change per unit of cell surface per unit of osmotic pressure outstanding between the cell and its medium.
Permeability to water as here defined and as somewhat differently defined by Northrop is approximately constant during swelling and shrinking, at least for the first several minutes of these processes.
Permeability is found to be independent of the osmotic pressure of the solution in which cells are swelling.
Water is found to leave cells more readily than it enters, that is, permeability is greater during exosmosis than during endosmosis.
METABOLISM AS RELATED TO CHROMOSOME STRUCTURE AND THE DURATION OF LIFE
Authors: Gowen John W. 
Published: May 2004

This paper presents the rates of CO2 production for four groups of Drosophila which differ in their chromosome constitutions. The four groups have metabolic rates which correlate with the balance of their chromosomes, the balanced chromosome groups of flies producing less CO2 than the unbalanced chromosome groups. It is concluded therefore that genic balance plays a prominent part in metabolic control.
The carbon dioxide rates are related to the duration of life within these groups. The results show that qualitatively the larger the production of CO2 per day the shorter the time which the flies are capable of living. The agreement is not exact quantitatively. Rubner's theory postulating a limit for the energy an organism is capable of metabolizing does not hold for the six classes of flies. The data show that the theory can be at most not more than a partial truth.
Cell size is found to show no direct correlation with the metabolic rates of the different fly cohorts.
ELECTRICAL VARIATIONS DUE TO MECHANICAL TRANSMISSION OF STIMULI
Authors: Osterhout W. J. V. , Hill S. E. 
Published: May 2004

Mechanical stimulation of Nitella often produces responses resembling propagated negative variations but traveling faster and going past a killed spot. They appear to result from a mechanical disturbance traveling along the cell and stimulating each spot it touches (i.e. the stimulus itself travels). They are called mechanical variations to distinguish them from propagated negative variations.
A mechanical disturbance may cause an irreversible change (death wave), but in traveling along the cell it may lose intensity and then produce only a reversible response (mechanical variation) which may eventually change to a propagated negative variation.
The all or none law does not apply to incomplete mechanical variations, for the response varies with the strength of the stimulus.
THE OCCURRENCE OF PORPHYRINS IN CULTURES OF C. DIPHTHERIAE
Authors: Coulter Calvin B. , Stone Florence M. 
Published: May 2004

A complex porphyrin which has not been hitherto described is found in liquid cultures of C. diphtheriae. The porphyrin is a combination of coproporphyrin with both iron and copper, and shows an oxidation-reduction change. This is the first report, as far as we are able to determine, of a porphyrin compound which contains both iron and copper in its molecule. Its source is in all probability the cytochome of the bacilli.
The content of porphyrin is proportional to the biological titer of the culture filtrate; the suggestion is offered that the toxin itself is derived from cytochrome.
PROTEIN COAGULATION AND ITS REVERSAL
Authors: Anson M. L. , Mirsky A. E. 
Published: May 2004

1. The globin prepared from hemoglobin by the acid acetone method is denatured globin.
2. The denaturation and coagulation of globin by acid acetone are reversible.
3. Soluble globin can be obtained from the acid acetone globin even if the globin is first precipitated by trichloracetic acid or heated to 100°C.
4. Hill and Holden's theory that they separated native globin from hemoglobin without any intermediate denaturation is not proven by their experiments.
THE PRODUCTION AND INHIBITION OF ACTION CURRENTS BY ALCOHOL
Authors: Osterhout W. J. V. , Hill S. E. 
Published: May 2004

Suitable concentrations of ethyl alcohol (1 to 1.5 M) applied to a spot on a cell of Nitella lower the P.D. enough to cause action currents. The alcohol then suppresses action currents arriving from other parts of the cell and acts as a block. After the alcohol is removed the normal P.D. and irritability return.
Similar experiments on the sciatic nerve and skin of the frog produced only a negative result.
THE ISOELECTRIC POINT OF A STANDARD GELATIN PREPARATION1
Authors: Hitchcock David I. 
Published: May 2004

Two samples of a standard gelatin were studied, both prepared according to published specifications and washed free from diffusible electrolytes. The isoelectric point of this material was determined in four ways.
1. The pH values of solutions of gelatin in water approached the limit 4.86 ± 0.01 as the concentration of gelatin was increased.
2. The pH values of acetate buffers were unchanged by the addition of gelatin only at pH 4.85 ± 0.01. This gives the isoionic point of Sørensen, which is the isoelectric point with respect only to hydrogen and hydroxyl ions.
3. Gels of this gelatin made up in dilute HCl or NaOH, or in dilute acetate buffers, exhibited maximum turbidity at pH 4.85 ± 0.03.
4. Very dilute suspensions of collodion particles in 0.1 per cent gelatin solutions made up in acetate buffers showed zero velocity in cataphoresis experiments only at pH 4.80 ± 0.01.
No evidence was found for the assumption that gelatin has two isoelectric points at widely separated pH values.
It is concluded that the isoelectric point of this standard gelatin is not far from pH 4.85.
PROTEIN COAGULATION AND ITS REVERSAL
Authors: Anson M. L. , Mirsky A. E. 
Published: May 2004

1. It is possible to prepare crystalline, soluble, heat-coagulable serum albumin from coagulated serum albumin.
2. In the cases so far studied, the more soluble a denatured protein, the more easily its denaturation can be reversed.
SALT EFFECTS ON EGGS AND NAUPLII OF ARTEMIA SALINA L
Authors: Boone Eleanor , Baas-Becking L. G. M. 
Published: May 2004

Eggs of Artemia salina L., the brine shrimp, are easily obtainable in large quantities. Ecdysis takes place in two stages: (a) extrusion of the inner membrane, and (b) ecdysis of the nauplius from that membrane. The conditions which allow for the former are much more varied than those for the latter.
Nauplii form in only solutions of a few sodium salts; and, in Mg, Ca, and Sr salts, potassium is very toxic.
The possible environment for the nauplii (1 M total molarity) has been ascertained for chlorides of Na, K, Mg, and Ca.
The facts observed account for the peculiar distribution of the organism.
THE PRESENCE OF A GELATIN-LIQUEFYING ENZYME IN CRUDE PEPSIN PREPARATIONS
Authors: Northrop John H. 
Published: May 2004

A protein fraction has been isolated from crude pepsin preparations which is about 400 times as active as crystalline pepsin in the lique-faction of gelatin.
The activity as measured by the digestion of casein, edestin or egg albumin is less than that of crystalline pepsin.
It is more resistant to alkali than the crystalline pepsin.
STUDIES ON MILK SECRETION
Authors: Gowen John W. , Tobey Elmer R. 
Published: May 2004

In this paper data are presented on cows receiving no food but having access to all of the water which they wished. The yield and composition of the milk were determined at various times during the periods of starvation. The composition of the milk showed changes which were progressive in the sense that they followed a definite course. They were characterized by a marked lowering in the amount of milk produced, by an increase in the total solids (chiefly an increase in the percentage of fat and ash, with a slight increase in proteins), and by a pronounced decrease in the lactose. The decrease in lactose corresponded with a decrease in the dextrose content of the blood, thereby supporting the conclusion that the lactose of milk has as its precursor dextrose of the blood. All the changes in milk composition during starvation can be directly related to the simultaneous changes in the blood.
The following companion paper on insulin and phloridzin as they affect milk secretion further develops these hypotheses.
STIMULATION BY HYDROCHLORIC ACID IN THE CATFISH, SCHILBEODES
Authors: Cole William H. , Allison James B. 
Published: May 2004

1. The reaction of the catfish, Schilbeodes gyrinus Mitchill, to hydrochloric acid over a wide range of concentrations (from pH 1.82 to pH 6.83) has been studied under experimental conditions which reduced to a minimum all other stimuli.
2. As the [H+J increases within the limits mentioned, the reaction time of the fish decreases. In other words, the rate of the stimulation processes is an increasing function of the hydrogen ion concentration.
3. The effective stimulus is the hydrogen ion, since NaCl solutions of equivalent concentration were not stimulating.
4. Stimulation by hydrochloric acid is therefore correlated with the potential of the cation resulting from dissociation of the acid molecule.
ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS
Authors: Whitaker D. M. 
Published: May 2004

1. The unfertilized eggs of Fucus vesiculosus, in the dark, consume about 5.2 mm.3 O2 per hour per 10 mm.3 eggs.
2. With an illumination of 100,000 foot candles in photosynthesis they liberate more than twice as much oxygen as they consume.
3. The actively swimming antherozoids or sperm of Fucus consume oxygen at a very high rate: 25.5 mm.3 O2 per hour per 10 mm.3 antherozoids.
4. Immediately following fertilization, in the dark, the Fucus eggs increase the rate of oxygen consumption to about 190 per cent of the prefertilization rate.
5. This rate for fertilized eggs, about 190 per cent, is maintained uniformly for 13 or 14 hours, after which there is a barely perceptible rise until 24 hours (when measurements ceased). At 18°C. 50 per cent of the spores in a population have completed the first cell division about 15 hours after fertilization.
ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS
Authors: Whitaker D. M. 
Published: May 2004

1. The rate of consumption of oxygen by unfertilized Nereis eggs is about 1.1 mm.3 O2 per hour per 10 mm.3 eggs.
2. Following fertilization the rate increases to 135 per cent or 145 per cent of the prefertilization rate, and continues to increase for 2 hours (the duration of the measurements).
ON THE PHYSICAL NATURE OF "CYTOTROPISM" AND ALLIED PHENOMENA AND THEIR BEARING ON THE PHYSICS OF ORGANIC FORM
Authors: Rashevsky N. 
Published: May 2004

From thermodynamical considerations expressions are derived for the forces which will act on a liquid drop suspended in another liquid, if the latter contains in solution a substance whose concentration is non-uniform. It is shown that forces of attraction and repulsion between two such drops may result, if the drops are seats of chemical reactions, which produce substances diffusing into the surrounding medium.
An estimate of the order of magnitude of such forces is made, and it is found that they may exceed the electrical forces which would result from the charges which the drops may possess.
A possible experimental method of studying such forces is suggested.
The possible connection of the above forces with those observed in the phenomena of "cytotropism," and their bearing on the physical explanation of organic form, especially of the phenomena of "induction," is briefly discussed.
THE EFFECT OF ADDED LOADS UPON THE GEOTROPIC ORIENTATION OF YOUNG GUINEA PIGS
Authors: Upton Morgan 
Published: May 2004

It has been found that young guinea pigs when progressing over a surface inclined at an angle α with the horizontal, orient upward in a way such that the path described by an oriented animal is at a mean angle θ with the base of the inclined surface. The magnitude of mean θ increases as the angle of inclination α increases. The function relating θ and α is compound, being made up of two sections with a break which corresponds to a change in the mode of progression of an animal over the surface of the plane.
If a load of constant relative mass is attached to the back of an animal, midway between the fore and hind legs, testing on an inclined surface reveals the fact that the magnitude of mean θ is increased over the entire range of stimulation, with the two values of mean θ (i.e. with and without added load) becoming more nearly equal as they approach 90° as a limiting value. The variation (P.E. of mean θ) is not sensibly changed by attaching a load to an orienting animal; for equal magnitudes of θ, under the two sets of test conditions, the P.E.'s are very nearly equal.
THE SPECTRAL SENSIBILITY OF THE SUN-FISH AS EVIDENCE FOR A DOUBLE VISUAL SYSTEM
Authors: Grundfest Harry 
Published: May 2004

1. An extension of a previously described method makes possible the measurement of the visibility function of Lepomis at high intensities of spectral illumination. This is accomplished by determining the relative energies of various spectral beams which will just produce a visual orienting response by the animal to the movement of a pattern composed of fine lines.
2. The function so determined is different from that obtained with a pattern composed of wide bars and spaces at a lower intensity level.
3. This difference furnishes direct and quantitative proof that the eye of Lepomis is a physiologically duplex visual system and parallels the known anatomical distinctions between the rods and cones.
4. A comparison of the visibility curves of the two systems indicates that both functions are similar in shape but that the cone curve is shifted to the red.
5. It is suggested that this relation between the two systems, which is also found in the human and the fowl, indicates that the photosensory substance is the same in each case for the rods and cones. According to this hypothesis, the shift of the cone curve is due to a common physical cause which depends on differences in the properties of the solvent media in the cones and in the rods.
DISSIMILARITY OF INNER AND OUTER PROTOPLASMIC SURFACES IN VALONIA. III
Authors: Damon E. B. 
Published: May 2004

Evidence that the inner and outer protoplasmic surfaces in Valonia are unlike is found in the high P.D. across the protoplasm when the external solution has the same composition as the vacuolar sap. Earlier experiments with artificial sap have been repeated, using natural as well as artificial sap. Good agreement between the data with the natural and the artificial solution was found both in the magnitude of the P.D.'s observed and in the shape of the P.D.-time curves. The P.D.'s, however, were considerably higher than the values formerly reported as usual, while the cells proved much less liable to alteration produced by exposure to sap. It is suggested that the cells used in the recent experiments were in a more vigorous condition, perhaps as a result of exposure to stronger illumination.
The interpretation of the shape of the P.D.-time curves, proposed in an earlier report, and based on the theory of protoplasmic layers, is further discussed. It is assumed that the fluctuations in P.D. are due to an increase in the concentration of K in the main body of the protoplasm.
THE ADSORPTION OF GELATIN BY COLLODION MEMBRANES
Authors: Palmer Albert H. 
Published: May 2004

An experimental study has been made of the adsorption of gelatin from solution at 37°C. by collodion membranes. In the case of membranes of high permeability, very high concentrations of gelatin were required to produce maximum adsorption, and the maximum amounts adsorbed were independent of the pH values of the solutions over the range 3.8 to 4.8. With membranes of low permeability, maximum adsorption was reached at lower gelatin concentrations, and the maximum amounts adsorbed varied with the pH, being lower on either side of the isoelectric point, over the range 3.8 to 6.6. The addition of salt in such experiments raised the maximum amount adsorbed to a value equal to that obtained with solutions at the isoelectric point in the absence of salt.
These experiments can be explained by, and seem to lend support to, the theory proposed by Loeb and further developed by Kunitz concerning the effects of pH and salt on the size of gelatin particles in solution.
ON THE EXCITATION OF TISSUE BY MEANS OF CONDENSER DISCHARGES
Authors: Blair H. A. 
Published: May 2004

Equations are derived for the capacity-voltage relations for stimulation of tissue by condenser discharges, using the hypothesis that the local excitatory process p grows under the influence of an applied potential V according to the equation,
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where K and k are constants. It is further assumed that the local excitatory process becomes adequate when it attains a value h ± α V where h and α are constants and V is the applied potential at the particular instant that the adequate value is attained. The equations so obtained are applied to the data of several authors on several types of tissue and the agreements obtained are sufficiently good. It is shown in one case that the direct current equation and the condenser discharge equation each derived from the above bases are consistent when applied to data from the same preparation.