bluuebunny/crossref_metadata_2025 huggingface dataset:
Platelet-collagen adhesion: evidence for participation of antigenically distinct entities.
Authors: Shadle P J , Barondes S H
Published: May 2004

Univalent antibody fragments prepared from a rabbit antiserum raised against whole human platelets completely inhibited adhesion of platelets to immobilized trimeric collagen in a defined, Mg2+-dependent, adhesion assay. An octylglucoside extract of whole platelets completely neutralized this antibody, and all neutralizing activity bound to immobilized wheat germ agglutinin. Further fractionation on concanavalin A gave rise to subfractions that each neutralized only partially at saturation, when tested against antibody concentrations that inhibit 50% of platelet-collagen adhesion. When tested against higher antibody concentrations that completely inhibited adhesion, each subfraction had no detectable neutralizing effect, although the combined subfractions neutralized completely. This and other evidence suggests that more than one platelet entity participates in platelet-collagen adhesion. Although distinct, they appear to play interdependent roles in a single adhesion process.
Biosynthesis of the D2-cell adhesion molecule: post-translational modifications, intracellular transport, and developmental changes.
Authors: Lyles J M , Linnemann D , Bock E
Published: May 2004

Posttranslational modifications and intracellular transport of the D2-cell adhesion molecule (D2-CAM) were examined in cultured fetal rat neuronal cells. Developmental changes in biosynthesis were studied in rat forebrain explant cultures. Two D2-CAM polypeptides with Mr of 187,000-210,000 (A) and 131,000-158,000 (B) were synthesized using radiolabeled precursors in cultured neurons. A and B were found to contain only N-linked complex oligosaccharides, and both polypeptides appeared to be polysialated as determined by [14C]mannosamine incorporation and precipitation with anti-polysialic acid antibody. The two polypeptides were sulfated in the trans-Golgi compartment and phosphorylated at the plasma membrane. D2-CAM underwent rapid intracellular transport, appearing at the cell surface within 35 min of synthesis. A and B were shown to be integral membrane proteins as seen by radioiodination by photoactivation employing a hydrophobic labeling reagent. In rat forebrain explant cultures, D2-CAM was synthesized as four polypeptides: A (195,000 Mr), B (137,000 Mr), C (115,000 Mr), and a group of polypeptides in the high molecular weight region (HMr) between 250,000 and 350,000. Peptide maps of the four polypeptides yielded similar patterns. Biosynthesis of C and HMr increased with age, relative to A and B. A and B were sulfated in embryonic brain, however, sulfation was not noticeable at postnatal ages. Phosphorylation, on the other hand, of A and B was observed at all ages examined. We suggest that D2-CAM function may be modified during development by changes in the relative synthesis of the different polypeptides, as well as by changes in their glycosylation and sulfation.
An extracellular retinol-binding glycoprotein in the eyes of mutant rats with retinal dystrophy: development, localization, and biosynthesis.
Authors: Gonzalez-Fernandez F , Landers R A , Glazebrook P A , Fong S L , Liou G I , Lam D M , Bridges C D
Published: May 2004

Interstitial retinol-binding protein (IRBP) is a soluble glycoprotein in the interphotoreceptor matrix of bovine, human, monkey, and rat eyes. It may transport retinol between the retinal pigment epithelium and the neural retina. In light-reared Royal College of Surgeons (RCS) and RCS retinal dystrophy gene (rdy)+ rats, the amount of IRBP in the interphotoreceptor matrix increased in corresponding proportion to the amount of total rhodopsin through postnatal day 22 (P22). In the RCS-rdy+ rats, the amount increased slightly after P23. However, in the RCS rats there was a rapid fall in the quantity of IRBP as the photoreceptors degenerated between P23 and P29. No IRBP was detected by immunocytochemistry in rats at P28. The amount of rhodopsin fell more slowly. Although retinas from young RCS and RCS-rdy+ rats were able to synthesize and secrete IRBP, this ability was lost in retinas from older RCS rats (P51, P88) but not their congenic controls. The photoreceptor cells have degenerated at these ages in the RCS animals, and may therefore be the retinal cells responsible for IRBP synthesis. The putative function of IRBP in the extracellular transport of retinoids during the visual cycle is consistent with a defect in retinol transport in the RCS rat reported by others.
Biosynthesis of von Willebrand protein by human endothelial cells: processing steps and their intracellular localization.
Authors: Wagner D D , Marder V J
Published: May 2004

Biosynthesis of von Willebrand protein by human umbilical vein endothelial cells involved distinct processing steps marked by the presence of several intermediate molecular species. Examination of endoglycosidase H sensitivity of these intracellular intermediates indicated that the processing steps occurred in at least two separate cellular compartments. In the pre-Golgi apparatus (most probably the endoplasmic reticulum), the high mannose carbohydrates were added onto the precursor monomer chains and the 260,000-mol-wt monomers dimerized by interchain disulfide bond formation. The other processing steps have been localized to the Golgi apparatus and later compartments (e.g., Weibel-Palade bodies). High mannose carbohydrate was converted to the complex type, leading to the appearance of a larger precursor subunit of 275,000 mol wt. The 275,000-mol-wt species was not formed if carbohydrate processing was inhibited by the ionophore monensin. From the large pool of dimers of precursor subunits, the high molecular weight multimers were built. These dimer molecules appeared to have free sulfhydryls which might have been involved in the interdimer disulfide bond formation. Simultaneously with multimerization, the precursor subunits were cleaved to the 220,000-mol-wt form. The cleavage of the pro-sequence was not likely to be an absolute requirement for von Willebrand protein multimerization or secretion, as the 275,000-mol-wt precursor subunit was present in secreted high molecular weight multimers of the protein.
Assembly properties of fluorescein-labeled tubulin in vitro before and after fluorescence bleaching.
Authors: Leslie R J , Saxton W M , Mitchison T J , Neighbors B , Salmon E D , McIntosh J R
Published: May 2004

Brain tubulin has been conjugated with dichlorotriazinyl-aminofluorescein (DTAF) to form a visualizable complex for the study of tubulin dynamics in living cells. By using several assays we confirm the finding of Keith et al. (Keith, C. H., J. R. Feramisco, and M. Shelanski, 1981, J. Cell Biol., 88:234-240) that DTAF-tubulin polymerizes like control tubulin in vitro. The fluorescein moiety of the complex is readily bleached by the 488-nm line from an argon ion laser. When irradiations are performed over short times (less than 1 s) and in the presence of 2 mM glutathione, a mixture of DTAF-tubulin and control protein (as occurs after microinjection of the fluorescent conjugate into living cells) will retain full polymerization activity. Slow bleaching (approximately 5 min) or bleaching without glutathione promotes formation of covalent cross-links between neighboring polypeptides and kills the polymerization activity of DTAF-tubulin, including some molecules that are neither cross-linked nor bleached. Even under conditions that damage DTAF-tubulin, however, DTAF-microtubules are not destroyed by bleaching. They will continue to elongate by addition of DTAF-tubulin subunits to their free ends, and they neither bind nor exchange subunits along their lateral surfaces. These results suggest that DTAF-tubulin is a suitable analog for tubulin, both in studies of protein incorporation and for investigations of fluorescence redistribution after photobleaching.
SV40 transformation of Swiss 3T3 cells can cause a stable reduction in the calcium requirement for growth.
Authors: Nicholson N B , Chen S , Blanck G , Pollack R
Published: May 2004

A well-characterized SV40-transformed Swiss 3T3 line, SV101, and its revertants were tested for the ability to grow in reduced Ca++ (0.01 mM). Transformants and revertants did not differ from the parent 3T3 line in their Ca++ requirements. All three classes of cells grew less well in low Ca++ than in regular Ca++ (2.0 mM). SV40 transformants were then selected for the ability to grow in reduced Ca++. This new class of transformants was found to grow in 1% serum, grow in soft agarose, have a reorganized actin cytoskeleton, and express viral T antigens, as well as grow well in low Ca++. One of the selected clones was found to be T antigen-negative, yet was transformed in the serum, anchorage, actin, and Ca++ assays. It is possible that this clone was a spontaneous transformant. However, Southern blot analysis revealed the presence of integrated SV40 DNA. In addition, this analysis revealed the absence of an intact early region fragment, which codes for the viral T antigens. One explanation of this result may be that the mechanism of viral transformation for growth in low Ca++ involves viral-host DNA interactions that may not require a fully functional T antigen. In this case SV40 integration may be acting as a nonspecific cellular mutagen.
ON THE DYNAMICS OF PHOTOSYNTHESIS
Authors: Osterhout W. J. V. , Haas A. R. C.
Published: May 2004

Minute amounts of photosynthesis in marine plants can be accurately measured by adding a little phenolphthalein to the sea water, and observing changes in the color of the indicator. In the case of fresh water aquatics bicarbonates are added.

By this method it is found that Ulva which has been kept in the dark begins photosynthesis as soon as it is exposed to sunlight and that the rate steadily increases until a constant speed is attained.

This may be explained by assuming that sunlight decomposes a substance whose products either catalyze photosynthesis or enter directly into the reaction.

Quantitative theories are developed in order to account for the facts.
LUTEAR CELLS AND HEN-FEATHERING
Authors: Boring Alice M. , Morgan T. H.
Published: May 2004

The experimental evidence had made clear that some substance is produced in the testis of the male Sebright that suppresses in him the development of the secondary sexual plumage of the cock of his species. The detection in his testis of lutear cells like those in hens makes the conclusion highly probable that it is these cells that cause the suppression of cock-feathering in both the Sebright male and in hens of all fowls. Genetic work by Morgan had shown that one or two Mendelian factor-differences are responsible for hen-feathering in the Sebright. These factor-differences produce their effects through the testes. The presence of these genetic factors, we now see, causes the testes of the Sebright to produce a kind of secretory cell that is ordinarily only produced in the female, or possibly to a slight extent in young males (Boring), or in numbers insufficient to suppress the male plumage in the testes of some ordinary cock birds (Reeves).
THE ANTAGONISM BETWEEN THYROID AND PARATHYROID GLANDS
Authors: Uhlenhuth Eduard
Published: May 2004

From the facts stated in this paper it is evident that the thymus gland of mammals contains a substance which is capable of producing tetany when fed to the larvæ of certain species of salamanders (Ambystoma opacum and Ambystoma maculatum). As long as the larvæ have not developed their own thymus glands, they are able, by means of some mechanism, to counterbalance the tetanic action of the thymus substance introduced in their food. When, however, the secretion from their own thymus glands is added to the thymus material introduced with the food, this mechanism of preventing tetany becomes inadequate and tetany ensues. In the larva of a third species of salamander, Ambystoma tigrinum, this mechanism will prevent tetany even when the larvæ are fed on thymus.

In mammals the parathyroids are known to prevent tetany and are supposed either to absorb the tetany-producing substance and thus prevent its action or to change it into another non-toxic substance. It is at least probable that in the amphibians the parathyroids play the same rôle. Larvæ of anuran amphibians, which develop their parathyroids soon after hatching, never show tetanic convulsions if they are fed on thymus, but in certain species of salamanders, whose parathyroids develop only during metamorphosis, the larvæ invariably have tetanic convulsions upon thymus feeding, while the metamorphosed animals never show tetany.

But in addition to the parathyroids the salamanders must possess still another mechanism which during the larval period inhibits the production of tetany by the animal's own thymus glands. In the larvæ of Ambystoma opacum and Ambystoma maculatum this mechanism is sufficient only to prevent tetany from the animal's own thymus, while in the larvæ of Ambystoma tigrinum it is capable of preventing tetany even when the larvæ are fed with thymus.

If the thymus is the organ by whose action tetany is produced, we can understand why tetany in human beings occurs far more frequently in children than in adults, since in the latter the thymus gland is replaced, at least to a great extent, by connective tissue. The relation of thymus to tetany may also possibly explain the occurrence of tetany during pregnancy; while the parathyroids of the mother may be sufficient to prevent tetany from her largely atrophied thymus, they may not be sufficient to prevent tetany from the excess of thymus substance furnished by the fetus to the blood of the mother.
FURTHER PROOF OF THE EXISTENCE OF A SPECIFIC TETANY-PRODUCING SUBSTANCE IN THE THYMUS GLAND
Authors: Uhlenhuth Eduard
Published: May 2004

The effect of the thymus gland in producing tetany is due to a specific tetany toxin produced by and contained in the thymus, and the thymus gland must be added to the group of glands for which the function of internal secretion has been demonstrated.
THE LAW CONTROLLING THE QUANTITY OF REGENERATION IN THE STEM OF BRYOPHYLLUM CALYCINUM
Authors: Loeb Jacques
Published: May 2004

1. A method is given which allows us to measure the influence of the mass of a leaf upon the quantity of shoots regenerated in an isolated piece of stem. This method consists in isolating a piece of stem with only two leaves left at the basal node and then splitting the stem lengthwise so that each half has one basal leaf. By leaving one leaf intact while the size of the sister leaf is reduced, the influence of the mass of the leaf upon the quantity of shoots regenerated by the stem can be measured.

2. This method has yielded the result that the mass of shoots regenerated at the apex of such a piece of stem increases under equal conditions and in equal time with the mass of the leaf, and is approximately proportional to the mass of the leaf.

3. Such an influence of the mass of the leaf upon the mass of shoots produced by the stem is only intelligible on the assumption that the growth of the regenerating shoot occurs at the expense of material furnished by the basal leaf.

4. This assumption is supported by two facts: first, that in the dark this influence of the leaf disappears more or less completely; and, second, that a leaf attached to the base of a regenerating stem after some time weighs markedly less than does a sister leaf completely detached from the stem, but otherwise under equal conditions.

5. This latter fact that a leaf when attached to the base of an excised piece of stem wilts more rapidly than when completely isolated is the reason that the proportionality between mass of a basal leaf and mass of shoot regenerated at the apex of an isolated piece of stem cannot always be demonstrated with the same degree of accuracy as the proportionality between the mass of completely isolated leaves and the mass of shoots they produce.

6. The material furnished by the leaf to the stem is not restricted to water but includes also the solutes, since not only the fresh weight but also the dry weight of the shoot regenerated by a piece of stem increases with the mass of the leaf attached to the base of the stem; and since not only the water contents but the dry weight of a leaf attached to the base of an excised piece of stem diminish when compared with the dry weight of a completely detached sister leaf.

7. The mass of shoots produced by an isolated piece of stem without leaf is small and almost negligible compared with the mass of shoots produced by the same piece of stem when a leaf of sufficient mass is attached to the base of the stem.
REVERSAL OF REACTION BY MEANS OF STRYCHNINE IN PLANARIANS AND STARFISH
Authors: Moore A. R.
Published: May 2004

Two cases have been described, that of the marine planarian Bdelloura and that of the starfish Asterias forbesii, in which strychnine reverses reciprocal inhibition. These facts indicate that the nervous systems of these invertebrates function in a manner similar to those of the earthworm and vertebrates. Moreover, it would seem that strychnine acts upon some chemical component of the neuron which is always present in synaptic structures but which also occurs in the simpler neurons of lower forms. The fact that strychnine is without this characteristic effect on such forms as medusa and sea anemone, indicates that the nervous systems of the starfish and planarian have chemical affinities with the vertebrates which the cœlenterates do not possess.
THE PHOTIC SENSITIVITY OF CIONA INTESTINALIS
Authors: Hecht Selig
Published: May 2004

1. Ciona possesses two means of responding to an increase in the intensity of illumination. One is by means of a local reaction; the other is by a retraction reflex of the body as a whole.

2. The "ocelli" are not photoreceptors. The photosensitive area is in the intersiphonal region containing the neural mass. This area contains no pigment.

3. The reaction time to light is composed of a sensitization period during which Ciona must be exposed to the light, and of a latent period during which it need not be illuminated in order to react to the stimulus received during the sensitization period.

4. The duration of the reaction time varies inversely as the intensity. Analysis shows the latent period to be constant. The relation between the sensitization period and the intensity follows the Bunsen-Roscoe rule.

5. During dark adaptation the reaction time is at first large, then it decreases until a constant minimum is reached.

6. A photochemical system consisting of a reversible reaction is suggested in order to account for the phenomena observed. This system includes a photosensitive substance and its precursor, the dynamics of the reaction following closely the peculiarities of the photosensitivity of Ciona.

7. It is shown that in order to produce a reaction, a constant ratio must be reached between the amount of sensitive substance broken down by the stimulus and the amount previously broken down.

8. From the chemical system suggested certain experimental predictions were made. The actual experiments verified these predictions exactly.

9. The results obtained with regularly repeated stimulation not only fail to show any basis for a learning process or for the presence of a "higher behavior," but follow the requirements of the photochemical system suggested before.
COMPARATIVE STUDIES ON RESPIRATION
Authors: Gustafson F. G.
Published: May 2004

1. In concentrations which are high enough to produce any effect, formaldehyde, ether, and acetone cause an increase, followed by a decrease, in the rate of respiration.

2. 3.65 per cent ether, which causes an increase with certain cultures, produces only a decrease with others.

3. The reaction producing an increase in the respiration with 7.3 per cent ether is a reversible process, while the reaction producing the decrease is not reversible.

4. 0.5 per cent caffeine produces only a decrease in respiration while a saturated solution causes an increase, which is followed by a decrease.
COMPARATIVE STUDIES ON RESPIRATION
Authors: Brooks Matilda Moldenhauer
Published: May 2004

1. In all the concentrations of ether studied (from 0.037 to 7.3 per cent) there is an increase in the rate of respiration of Bacillus subtilis followed by a decrease.

2. In 7.3 per cent ether in tap water there is an extraordinary increase in the output of CO2 (amounting to 50 times the normal). This does not occur when 0.85 per cent NaCl is added, which indicates antagonism between ether and NaCl.

3. Ether is toxic in low concentrations (0.037 to 1.1 per cent) and high concentrations (3.65 to 7.3 per cent) but in intermediate concentrations (1.1 to 3.65 per cent) stimulates growth.
COMPARATIVE STUDIES ON RESPIRATION
Authors: Thomas Helen Stillwell
Published: May 2004

These experiments show that 7.3 and 3.65 per cent ether solutions cause an increase in respiration followed by a decrease. The results agree with those of Haas on Laminaria, of Gustafson on higher fungi, and of Mrs. Brooks on bacteria.

They do not agree with the theory of Verworn that anesthesia is a kind of asphyxia and that it decreases respiration.
COMPARATIVE STUDIES ON RESPIRATION
Authors: Irwin Marian
Published: May 2004

1. The experiments on frog tadpoles show that with 0.15, 0.37, and 0.55 per cent ether solutions there is a decrease in CO2 output. The effect is reversible. With these concentrations the breathing movements and body movements remained normal during the experiment. In 3.65 and 7.3 per cent ether there is a decrease of respiration followed by an increase which in turn is followed by a decrease. The increase may reach about three times the normal rate. The increase in the CO2 output is accompanied by the peeling of the skin. The effect is irreversible.

2. Experiments on an aquatic insect, Dineutes assimilis Aube, show that in 7.3 per cent ether there is a decrease followed by an increase which in turn is followed by a decrease. There is no apparent disintegration of structures in the organism accompanying the increase. The effect is irreversible.

3. The experiments on frog eggs with 7.3 per cent ether show a result similar to that found in aquatic insects.

4. Experiments on Fundulus embryos show that with 0.73 per cent ether there is a reversible decrease in the rate of CO2 production. In 3.65 per cent ether there is a temporary decrease followed by an increase, after which the rate begins to fall off. In 7.3 per cent ether there is an immediate increase amounting to 307 per cent which is followed by a decrease. The increase in the 3.65 and 7.3 per cent ether is accompanied by irreversible changes leading to death. The decrease found in 0.73 per cent ether is not sufficient to cause narcosis, as is shown by experiments on which the same decrease is produced by lowering the temperature.

5. These experiments show that narcosis is not due to asphyxia. The action of anesthetics is due to some other cause than the effect on respiration.

There is a difference between the animals studied and the plants described in this series of articles, since in animals the increase in the CO2 output is accompanied by irreversible changes leading to death, while this is not necessarily the case in plants. The reversible (narcotic) action of ether on the animals studied was accompanied by a decrease in the carbon dioxide output; in plants this is not ordinarily the case.

These facts are of considerable interest, but their interpretation must be left to future investigation.
THE TEMPERATURE COEFFICIENT OF PHOTOSYNTHESIS
Authors: Osterhout W. J. V. , Haas A. R. C.
Published: May 2004

The temperature coefficient of photosynthesis in Ulva (between 17° and 27°C.) is 1.81. This may be explained by assuming that the process involves a light reaction with a low coefficient followed by an ordinary reaction with a high coefficient.
THE PHYSIOLOGICAL BASIS OF MORPHOLOGICAL POLARITY IN REGENERATION. I
Authors: Loeb Jacques
Published: May 2004

1. In Bryophyllum calycinum two apical leaves suppress the shoot formation in all the dormant buds situated basally from the leaf; one apical leaf suppresses the shoot formation in the basal buds situated in the same half of the stem where the leaf is, and, if one-half of the petiole of such a leaf is removed, the growth of basal buds in one quadrant of the stem is suppressed.

2. This inhibitory influence of a leaf upon shoot formation in the basal part of a stem is diminished or disappears when the mass of the leaf is reduced below a certain limit.

3. The inhibitory influence of an apical leaf upon the growth of shoots in horizontally suspended stems is greater when the leaf is on the upper than when it is on the lower side of the stem.

4. All these facts suggest the possibility that the inhibitory influence of the leaf upon shoot formation is due to inhibitory substances secreted by the leaf and carried by the sap from the leaf towards the base of the stem.

5. An apical leaf accelerates root formation in the basal part of a stem and this accelerating effect increases with the mass of the leaf.

6. This inhibitory influence of a leaf upon shoot formation and the favoring influence upon root formation in the more basally situated parts of the stem is one of the factors determining the polar character of regeneration.
COMPARATIVE STUDIES ON RESPIRATION
Authors: Irwin Marian
Published: May 2004

In petals of Salvia high concentrations of ether cause an increase in oxygen consumption and in the production of CO2, while at the same time a decrease occurs in the acidity of the cell contents.
DECREASE OF PERMEABILITY AND ANTAGONISTIC EFFECTS CAUSED BY BILE SALTS
Authors: Osterhout W. J. V.
Published: May 2004

Sodium taurocholate is able to produce a decrease in permeability and to antagonize NaCl. This confirms the hypothesis that antagonistic relations can be predicted from studies on the permeability of pure substances.
RELATION BETWEEN THYROID GLAND, METAMORPHOSIS, AND GROWTH
Authors: Uhlenhuth Eduard
Published: May 2004

1. Two substances are involved in amphibian metamorphosis as studied in Ambystoma opacum: first, iodine, which is taken up by the food, and second, an excretor substance, which is evolved during the processes of growth and serves to induce the excretory function of the thyroid gland.

2. This explains why in larvæ, whose metamorphosis is inhibited by lack of iodine, growth is checked at the time when metamorphosis should occur; for at this time the excretor substance commences to act and this results, if iodine is absent, in the excretion by the thyroid of toxic substances which cause the breakdown of proteins and consequently a decrease in size of the larvæ.

3. Larvæ whose metamorphosis is inhibited by extirpation of the thyroid or by the hereditary lack of a thyroid (as is the case in Typhlomolge) can grow normally, since in them the action of the excretor substance cannot result in the excretion by the thyroid of a toxic growth-inhibiting substance.

4. At low temperature less excretor substance is produced than at high temperature during an equal rate of growth; therefore larvæ kept at low temperature reach a larger size than larvæ kept at high temperature, before they metamorphose.
AMPHOTERIC COLLOIDS
Authors: Loeb Jacques
Published: May 2004

1. A method is given by which the amount of equivalents of metal in combination with 1 gm. of a 1 per cent gelatin solution previously treated with an alkali can be ascertained when the excess of alkali is washed away and the pH is determined. The curves of metal equivalent in combination with 1 gm. of gelatin previously treated with different concentrations of LiOH, NaOH, KOH, NH4OH, Ca(OH)2, and Ba(OH)2 were ascertained and plotted as ordinates, with the pH of the solution as abscissæ, and were found to be identical. This proves that twice as many univalent as bivalent cations combine with the same mass of gelatin, as was to be expected.

2. The osmotic pressure of 1 per cent solutions of metal gelatinates with univalent and bivalent cation was measured. The curves for the osmotic pressure of 1 per cent solution of gelatin salts of Li, Na, K, and NH4 were found to be identical when plotted for pH as abscissæ, tending towards the same maximum of a pressure of about 325 mm. of the gelatin solution (for pH about 7.9). The corresponding curves for Ca and Ba gelatinate were also found to be identical but different from the preceding ones, tending towards a maximum pressure of about 125 mm. for pH about 7.0 or above. The ratio of maxi mal osmotic pressure for the two groups of gelatin salts is therefore about as 1:3 after the necessary corrections have been made.

3. When the conductivities of these solutions are plotted as ordinates against the pH as abscissæ, the curves for the conductivities of Li, Na, Ca, and Ba gelatinate are almost identical (for the same pH), while the curves for the conductivities of K and NH4 gelatinate are only little higher.

4. The curves for the viscosity and swelling of Ba (or Ca) and Na gelatinate are approximately parallel to those for osmotic pressure.

5. The practical identity or close proximity of the conductivities of metal gelatinates with univalent and bivalent metal excludes the possibility that the differences observed in the osmotic pressure, viscosity, and swelling between metal gelatinates with univalent and bivalent metal are determined by differences in the degree of ionization (and a possible hydratation of the protein ions).

6. Another, as yet tentative, explanation is suggested.
THE SELECTIVE ACTION OF NICOTINE ON THE CENTRAL NERVOUS SYSTEM OF THE SQUID, LOLIGO PEALII
Authors: Moore A. R.
Published: May 2004

1. In specimens of freshly hatched squid, Loligo pealii, nicotine acts upon the cerebral ganglia alone.

2. After 1 minute in the nicotine solution 1:500,000, the latent period for the mantle spasm is independent of the time spent in the solution.

3. The mantle spasm is conditioned by a chemical reaction, since the temperature coefficient of the process has a magnitude of about 2.8.

4. The velocity of the process which brings about the mantle spasm varies as the cube root of the concentration of the nicotine.
ANTAGONISM BETWEEN ALKALOIDS AND SALTS IN RELATION TO PERMEABILITY
Authors: Osterhout W. J. V.
Published: May 2004

Certain alkaloids which decrease permeability are able to antagonize NaCl. In this respect they resemble salts which decrease permeability, for it has been shown that such salts antagonize NaCl.
AMPHOTERIC COLLOIDS
Authors: Loeb Jacques
Published: May 2004

1. When we plot the values of osmotic pressure, swelling, and viscosity of gelatin solutions as ordinates over the pH as abscissæ, practically identical curves are obtained for the effect of monobasic acids (HCl, HBr, HNO3, and acetic acid) on these properties.

2. The curves obtained for the effect of H2SO4 on gelatin are much lower than those obtained for the effect of monobasic acids, the ratio of maximal osmotic pressures of a 1 per cent solution of gelatin sulfate and gelatin bromide being about 3:8. The same ratio had been found for the ratio of maximal osmotic pressures of calcium and sodium gelatinate.

3. The curves representing the influence of other dibasic and tribasic acids, viz. oxalic, tartaric, succinic, citric, and phosphoric, upon gelatin are almost identical with those representing the effect of monobasic acids.

4. The facts mentioned under (2) and (3) permit us to decide between a purely chemical and a colloidal explanation of the influence of acids on the physical properties of gelatin. In the former case we should be able to prove, first, that twice as many molecules of HBr as of H2SO4 combine with a given mass of gelatin; and, second, that the same number of molecules of phosphoric, citric, oxalic, tartaric, and succinic acids as of HNO3 or HCl combine with the same mass of gelatin. It is shown in the present paper that this is actually the case.

5. It is shown that gelatin sulfate and gelatin bromide solutions of the same pH have practically the same conductivity. This disproves the assumption of colloid chemists that the difference in the effect of bromides and sulfates on the physical properties of gelatin is due to a different ionizing and hydratating effect of the two acids upon the protein molecule.
ON THE CONTROL OF THE RESPONSE TO SHADING IN THE BRANCHIÆ OF CHROMODORIS
Authors: Crozier W. J.
Published: May 2004

The branchial plumes of Chromodoris respond, by contraction, to a decrease in light intensity. This response is obliterated by high temperatures (above 32°) and by direct sunlight, and is possible only within a limited range of alkalinity of the sea water. A concealing retraction of the whole gill-crown is reflexly determined by the self-contraction of the individual plumes under "optimal" conditions of light, temperature, and alkalinity. This protective response of the branchiæ is superimposed upon their simple system of fundamental activities (protrusion, retraction) apparently concerned with regulating the respiratory exchange of the nudibranch.
THE RESPIRATORY RATE OF THE SCIATIC NERVE OF THE FROG IN REST AND ACTIVITY
Authors: Moore A. R.
Published: May 2004

1. With the indicator method of Haas, the rates of carbon dioxide production have been measured in the case of the sciatic nerve, various parts of the brain, and the sartorius muscle of the frog. The rate of respiration of the sciatic nerve is from 10 to 30 per cent of that of the other tissues, varying somewhat with the individual.

2. Stimulation of the sciatic nerve with induction shocks sufficient to induce tetanus of the muscle does not increase the output of carbon dioxide from the sciatic nerve, even if continued as long as 30 minutes. Sartorius muscle used as a control showed a marked increase in carbon dioxide production upon relaxation after contraction resulting from such stimulation.

3. These facts indicate that the nerve impulse does not depend upon processes leading to the production of carbon dioxide.
THE ETCHING OF MARBLE BY ROOTS IN THE PRESENCE AND ABSENCE OF BACTERIA
Authors: Fred E. B. , Haas A. R. C.
Published: May 2004

In a study of the effect of soil bacteria upon the etching power of the roots of Canada field peas upon polished marble, it has been shown that the presence of the bacteria increases the etching power of the roots.
THE NATURE OF THE LATENT PERIOD IN THE PHOTIC RESPONSE OF MYA ARENARIA
Authors: Hecht Selig
Published: May 2004

The latent period in the response of Mya to illumination varies inversely as the duration of the exposure to which it is subjected. The reciprocal of the latent period, measuring the velocity of the process which underlies it, is a linear function of the exposure period. Since the duration of the exposure represents the amount of photochemical activity, it is concluded that the substances formed at that time act to catalyze a chemical reaction which determines the duration of the latent period.

This explanation is in accord with the previous work on the photochemical reaction and with the effect of temperature on the latent period. As a result of the combined investigations there is presented a concrete hypothesis for the mechanism of photic reception in Mya.
THE EFFECT OF TEMPERATURE ON THE LATENT PERIOD IN THE PHOTIC RESPONSE OF MYA ARENARIA
Authors: Hecht Selig
Published: May 2004

1. The effect of temperature on the reaction time of Mya to light is mainly confined to the latent period. The sensitization period, representing a photochemical process, is changed comparatively little.

2. The relation between the latent period and the temperature is adequately expressed by the Arrhenius equation, for temperatures below 21°C. Above this temperature, the latent period becomes increasingly longer than is required by the Arrhenius formula when µ = 19,680.

3. These deviations, occurring above the highest environmental temperature of Mya, are explained on the assumption that the principal product formed during the latent period is inactivated by heat.

4. Calculation of the velocity of the hypothetical inactivation reaction at different temperatures shows that it also follows the Arrhenius rule when µ = 48,500. This value of µ corresponds to those generally found for spontaneous inactivations and destructions.
THE PHYSIOLOGICAL BASIS OF MORPHOLOGICAL POLARITY IN REGENERATION. II
Authors: Loeb Jacques
Published: May 2004

1. The experiments show that the mass of air roots formed in a stem increases with the mass of the leaf attached to the stem, though it has not been possible to establish an exact mathematical relation between the two masses, owing to unavoidable sources of error.

2. Darkened leaves do not increase the mass of roots formed.

3. In stems suspended horizontally air roots appear on the lower side of the stem, with the exception of the cut end where they usually appear around the whole circumference of the stem. When the lower half of a stem suspended horizontally is cut off, roots are formed on the upper side. It is shown by experiments on leaves suspended horizontally that the more rapidly growing roots and shoots on the lower side inhibit the root and shoot formation in the upper half of such a leaf; and likewise the more rapid formation of roots on the lower side of a horizontally suspended stem seems to account for the inhibition of root formation on the upper side of such a stem. Likewise the more rapid growth of shoots on the upper side of a stem suspended horizontally is likely to inhibit the growth of shoots on the lower side.

4. Each leaf contains in its axil a preformed bud capable of giving rise to a root, which never grows out in the normal stem on account of the inhibitory influence of the normal roots at the base of the plant. These dormant root buds are situated above (apically from) the dormant shoot bud. The apical root buds can be caused to develop into air roots when a piece of stem is cut out from a plant from which the leaves except those in the basal node of the piece are removed. The larger these basal leaves the better the experiments succeed.

5. These apical air roots grow out in a few days, while the roots at the basal end of the stem (which in our experiments dip into water) grow out about a week later. As soon as the basal roots grow out in water they cause the air roots in the more apical region of the stem to dry out and to disappear.

6. In addition to the basal roots, basal nodes have also an inhibitory effect on the growth of the dormant root buds in the apical region of a stem. This is indicated by the fact that a stem with one pair of leaves near the base will form apical air roots more readily when no node is situated on the stem basally from the leaf than if there is a node basally from the leaf.
STUDIES ON ENZYME ACTION
Authors: Noyes Helen Miller , Lorberblatt I. , Falk K. George
Published: May 2004

The hydrolyzing actions of various preparations of the adult eel were studied on ten esters in the usual way. The results are presented in the form of curves for the relative actions and in a table for the absolute actions obtained in one complete experiment.

The separation of the enzyme material in some cases into an active portion and a co-enzyme, the mixture showing greater actions on some esters than the sums of the individual actions, is described and discussed.
FURTHER STUDIES ON THE INHIBITION OF CYPRIDINA LUMINESCENCE BY LIGHT, WITH SOME OBSERVATIONS ON METHYLENE BLUE
Authors: Harvey E. Newton
Published: May 2004

1. Eosin, erythrosin, rose bengale, cyanosin, acridine, and methylene blue act photodynamically on the luminescence of a Cypridina luciferin-luciferase solution. In presence of these dyes inhibition of luminescence, which without the dye occurs only in blue-violet light, takes place in green, yellow, orange, or red light, depending on the position of the absorption bands of the dye.

2. Inhibition of Cypridina luminescence without photosensitive dye in blue-violet light, or with photosensitive dye in longer wave-lengths, does not occur in absence of oxygen. Light acts by accelerating the oxidation of luciferin without luminescence. Eosin or methylene blue act by making longer wave-lengths effective, but there is no evidence that these dyes become reduced in the process.

3. The luciferin-oxyluciferin system is similar to the methylene white-methylene blue system in many ways but not exactly similar in respect to photochemical change. Oxidation of the dye is favored in acid solution, reduction in alkaline solution. However, oxidation of luciferin is favored in all pH ranges from 4 to 10 but is much more rapid in alkaline solution, either in light or darkness. There is no evidence that reduction of oxyluciferin is favored in alkaline solution. Clark's observation that oxidation (blueing) of methylene white occurs in complete absence of oxygen has been confirmed for acid solutions. I observed no blueing in light in alkaline solution.
THE INFLUENCE OF LIGHT, TEMPERATURE, AND OTHER CONDITIONS ON THE ABILITY OF NITELLA CELLS TO CONCENTRATE HALOGENS IN THE CELL SAP
Authors: Hoagland D. R. , Hibbard P. L. , Davis A. R.
Published: May 2004

1. By the use of a special analytical technique it has been possible to study the accumulation of halogens in the cell sap of Nitella.

2. From a dilute solution, Br may be accumulated in the sap in a concentration much greater than that of the external solution. The conductivity of the sap may be markedly increased by such accumulation. The process is a slow one so that a month or more may be required to approach equilibrium.

3. Cl may be lost from the cell as a result of the accumulation of Br and vice versa. Other reciprocal relations between Cl and Br are indicated.

4. At equilibrium practically as much Br accumulated in the sap with an external solution containing 1 milli-equivalent of Br as with one containing 5 milli-equivalents.

5. Light energy was indispensable to the accumulation of Br. The temperature coefficient was characteristic of a chemical process.
THE EFFECT OF THE pH ON THE GERMICIDAL ACTION OF SOAPS
Authors: Eggerth Arnold H.
Published: May 2004

1. The effect of the pH on the germicidal action of soaps has been studied. The lower members of the series were found to be most active in acid solution; the higher members, in alkaline. The point of transition varied with the test organism used.

2. This is probably due to the effect of the pH on the dissociation residue and on the solubility of the soap. The dissociation residue may affect the germicidal titer by modifying the surface tension, the penetration into the bacteria, and the partition coefficient of the germicide between bacteria and water.

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THE SWELLING PRESSURE OF GELATIN AND THE MECHANISM OF SWELLING IN WATER AND NEUTRAL SALT SOLUTIONS
Authors: Northrop John H. , Kunitz M.
Published: May 2004

1. A method is described for measuring the swelling pressure of solid gelatin.

2. It was found that this pressure increases rapidly between 15° and 37°C., and that the percentage change is nearly independent of the concentration of gelatin.

3. It is suggested that this pressure is due to the osmotic pressure of a soluble constituent of the gelatin held in the network of insoluble fibers, and that gelatin probably consists of a mixture of at least two substances or groups of substances, one of which is soluble in cold water, does not form a gel, and has a low viscosity and a high osmotic pressure. The second is insoluble in cold water, forms a gel in very low concentration, and swells much less than ordinary gelatin.

4. Two fractions, having approximately the above properties, were isolated from gelatin by alcohol precipitation at different temperatures.

5. Increasing the temperature and adding neutral salts greatly increase the pressure of the insoluble fraction and have little effect on that of the soluble fraction.

6. Adding increasing amounts of the soluble fraction to the insoluble one results in greater and greater swelling.

7. These results are considered as evidence for the idea that the swelling of gelatin in water or salt solutions is an osmotic phenomenon, and that gelatin consists of a network of an insoluble substance enclosing a solution of a soluble constituent.
THE EFFECT OF pH ON THE PERMEABILITY OF COLLODION MEMBRANES COATED WITH PROTEIN
Authors: Hitchcock David I.
Published: May 2004

The permeability of gelatin-coated collodion membranes, as measured by the flow of water or of dilute solutions through the membranes, has been found to vary with the pH of the solutions. The permeability is greatest near the isoelectric point of the protein; with increasing concentration of either acid or alkali it decreases, passes through a minimum, and then increases. These variations with pH are qualitatively in accord with the assumption that they are due to swelling of the gelatin in the pores of the membrane, the effects of pH being similar to those observed by Loeb on the swelling of gelatin granules. Indications have been found of a similar variable permeability in the case of membranes coated with egg albumin, edestin, serum euglobulin, and serum albumin.
TEMPERATURE CHARACTERISTICS FOR SPEED OF MOVEMENT OF THIOBACTERIA
Authors: Crozier W. J. , Stier T. J. B.
Published: May 2004

The speed of translatory movement of Beggiatoa alba is governed by temperature in such a way that between 5° and 33° the temperature characteristics µ = 16,100 and µ = 8,400 respectively obtain for the temperature ranges 5° to 16.5° and 16.5° to 33°. The "break" at 16°–17° is emphasized by the occurrence of a wider latitude of variation in speed above this temperature. Above 16° the progression of Thiothrix yields µ = 8,300. The possible relation of these values to that previously obtained for similar movement in (photosynthetic) Oscillatoria is commented upon.
CONCERNING THE INFLUENCE OF POLARIZED LIGHT ON THE GROWTH OF SEEDLINGS
Authors: Macht David I.
Published: May 2004

While these experiments are not exhaustive, a sufficient number have been made to warrant the statement that the effect of polarized light of the visible spectrum on the growth of various seedlings and

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more particularly on the growth of Lupinus albus is somewhat different from that of non-polarized light. This is especially convincing in view of the results obtained with double sets of plants which were alternately exposed to polarized and non-polarized lights of the same intensities and at the same temperature. In every experiment thus performed the set which was placed in a polarizing chamber grew better. It is, furthermore, interesting to note that the phenomenon above observed did not take place when the seed portion of the plants was protected from light by wrapping with tinfoil. This agrees well with previous findings concerning the action of diastase on starch in polarized light. The above researches will be continued on a more elaborate scale but the results so far obtained are deemed worthy of publication in the form of a preliminary communication at the present time.
ON CURVES OF GROWTH, ESPECIALLY IN RELATION TO TEMPERATURE
Authors: Crozier W. J.
Published: May 2004

The velocity of growth, taken as the reciprocal of the time required to attain a given size or stage of development, obeys with some exactness the Arrhenius equation for relation to temperature. The values of µ, and the type of "breaks" found in the curves connecting velocity and temperature, are similar to those found in the case of various other vital activities. More precise data, particularly from experiments in which parts of the given developmental stadium are passed at different temperatures, may strengthen present indications that this relationship is not absolute. It is pointed out that the equation for an autocatalytic process, taken as descriptive for growth, predicts particular sorts of deviation under these conditions, which have in one instance been obtained experimentally; and may at the same time nevertheless permit the apparent temperature characteristic for (average) growth velocity to agree rather closely with that for one of the two velocity constants present in the correct autocatalytic equation.