bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Central Nervous System and Regeneration in Crustacea
Authors: Needham A. E. 
Published: April 2021

ABSTRACTThe neural influence on the rate of regeneration of a limb in Asellus emanates from the segmental ganglion. It is independent of other centres of the c.n.s. Operations on the animal cause a non-specific retardation of all limbs regenerating immediately afterwards. The immediate cause is probably haemorrhage, since the effect is both systemic and proportional to the severity of injury. This general retardation acts differentially on a series of limbs, in proportion to their normal regeneration-rates. It has been possible to obtain a quantitative measure of this ‘differential inhibition’.
The Influence of Dissolved Oxygen on the Respiratory Movements of Caddis Larvae
Authors: Fox H. Munro , Sidney Jasmine 
Published: April 2021

ABSTRACT
Caddis larvae which bear cases ventilate their gills by undulatory movements of the abdomen. These respiratory movements produce a stream of water flowing out through the posterior opening of the case. In well-aerated water the movements are intermittent, periods of undulation alternating with pauses. In poorly aerated water the pauses become shorter.
Osmotic Relations in Molluscan Contractile Tissues
Authors: Pilgrim R. L. C. 
Published: April 2021

ABSTRACT
The general problem initiating these researches was outlined in the previous paper (Pilgrim, 1953). The following pages describe the action of variations in osmotic pressure of the surrounding fluid on the gill cilia of three lamellibranch species of contrasting ecological distribution. Details of the media used are given in an Appendix to the previous paper.
The Occurrence of Blood Groups in Cats
Authors: Holmes R. 
Published: April 2021

ABSTRACT
Methods are described which have been used to investigate isoagglutination reactions of the blood of cats. Evidence is presented which indicates that cats possess at least three groups. The methods and results of earlier workers which indicated that grouped isoagglutinins did not occur in cats have been criticized.
A genetical system for the cat groups similar to the human ABO system is shown to be untenable.
Two other possible systems similar to the A1A2O, and to the Rh models of humans are suggested and briefly discussed.
Active Transport of Potassium by the Malpighian Tubules of Insects
Authors: Ramsay J. A. 
Published: April 2021

ABSTRACT
The concentrations of sodium and potassium in the haemolymph and in the urine have been measured in eight species of insect. The concentration of potassium in the urine is always greater than in the haemolymph. The concentration of sodium in the urine is generally less than in the haemolymph. In seven of the species the difference of electrical potential across the wall of the tubule has also been measured. In these seven species the results lead to the conclusion that potassium is actively secreted into the tubule. It is very probable that the same is true in the eighth case. It seems likely that the excretion of sodium can be brought about by passive diffusion into the tubule.
Distributed ‘End-Plate Potentials’ of Crustacean Muscle Fibres
Authors: Fatt P. , Katz B. 
Published: April 2021

ABSTRACT
Crustacean muscles are known to produce powerful contractions without propagated action potentials (Wiersma, 1941a; Katz & Kuffler, 1946 ; Katz, 1949). It has been suggested (Wiersma, 1941a) that this type of response is made possible by the presence of nerve endings which are widely distributed along the surface of the muscle fibres. When nerve impulses arrive at the endings, a local depolarization is produced in the muscle fibre and in turn gives rise to contraction. This depolarization will be referred to as ‘end-plate potential’ (e.p.p.) by analogy with the e.p.p. of vertebrate muscle. A sufficiently large e.p.p. initiates a spike potential (Katz & Kuffler, 1946), which serves to strengthen the muscle response and, probably, to level out local inequalities in the fibre rather than to conduct excitation (cf. Fatt & Katz, 1953).
Metabolism of the Black Snake Embryo
Authors: Clark Hugh 
Published: April 2021

ABSTRACTVery few data exist on the nitrogenous excreta of reptilian embryos. Tomita (1929) indicates a substantial urea excretion by the turtle Chelonia, but no data are available for saurian reptiles. They have been presumed (Fiske & Boyden, 1926) to excrete uric acid because ‘a substance as soluble and diffusible as urea could not possibly replace it (uric acid) as an end product when the organism and its excretions are confined to a closed system, the walls of which are only permeable to matter in the gaseous state’. Needham (1931) estimates that the chick urea concentration would reach 165 mg. % if it excreted only urea, and intimates that such an accumulation in a cleidoic egg would be pathological.
The Diurnal Rhythm of Activity of Mayfly Nymphs
Authors: Harker Janet E. 
Published: April 2021

ABSTRACT
Moon (1940) has shown that nymphs of Ecdyonurus and Baetis move more during the night than the day under natural conditions, and he conjectured some indirect relationship between the stage of development and activity. This investigation has been undertaken as an attempt to discover the range of the diurnal periodicity of movement and the conditioning factors.
The Inorganic Constituents of the Sea-Urchin Egg
Authors: Rothschild Lord , Barnes H. 
Published: April 2021

ABSTRACT
The principal inorganic constituents of the unfertilized egg of Paracentrotus lividus have been analysed by chemical methods. The results of the analyses, in millimoles per kg. of water in the eggs (dry weight of eggs, 24 %; density, 1 ·09), were : The figures in brackets are the concentrations of the same substances in Roscoff sea water, chlorinity 19·37%, in the same units. The total phosphorus content of the eggs was about 2 mg./ml. eggs, somewhat over half of this being acid-soluble phosphorus.
Osmotic and Ionic Regulation in the Isopod Crustacean Ligia Oceanica
Authors: Parry G. 
Published: April 2021

ABSTRACT
Osmotic pressure of the blood of Ligia oceanica, measured by the freezingpoint depression, has a mean value of Δ 2·15 ±0·04° C. (≡ 3·58 % NaCl on weight/ volume basis). Osmotic pressure of Ligia blood is much higher than that of other terrestrial isopods: Oniscussp. Δ1·04° C.; Armadillidiumsp. Δ1·18° C. -, Porcellio sp. Δ1·30° C. or of the fresh-water Asellus sp. Δ0·500 C. The osmotic pressure of the blood increases during the process of moulting, but no subsequent decrease is observed in the 4 days following. Animals kept at low humidities lose water. They may be desiccated without permanent adverse effects until Δblood is 3·48° C. (≡ 5·8% NaCl). Recovery to a normal level takes about 24 hr. in moist conditions. In well-aerated sea water between 50 and 100% concentration, animals survive without much alteration in Δblood. Above and below this range Δblood rises and falls. In animals kept on filter-paper moistened with distilled water Δblood may fall to 1·44° C. (=2’4% NaCl) without permanent adverse effects. Analyses of inorganic ions in the blood show that sodium, potassium and chloride are all higher in concentration than in sea water; calcium is much more concentrated ; and magnesium and sulphate much reduced.
Active Transport of Water by the Malpighian Tubules of the Stick Insect, Dixippus Morosus (Orthoptera, Phasmidae)
Authors: Ramsay J. A. 
Published: April 2021

ABSTRACT
Single Malpighian tubules of the stick insect have been studied as preparations isolated in drops of haemolymph under liquid paraffin. Measurements of osmotic pressure have been made on haemolymph and urine. The urine is more or less isotonic with the haemolymph over a wide (45-145%) range of osmotic pressure. But in a majority of cases the urine is slightly but significantly hypotonic to the haemolymph. From these and other observations it is concluded that water must be actively transported across the wall of the tubule. The implications of this conclusion are discussed. The normal rate of urine production is of the order of 0.07 × 10-3 cu.mm./sq.mm./min. The rate increases with increasing dilution of the haemolymph and vice versa. Urine production normally ceases, probably as a result of distension of the tubule, when the pressure in the lumen rises to about 20 cm. H2O.
The Influence of Water and Light and the Pituitary Upon the Pigmentary System of the Common Toad (Bufo Bufo Bufo)
Authors: Rowlands Anne 
Published: April 2021

ABSTRACT
Bufo bufo bufo shows no melanophore response to moisture. The severance of the optic nerve or the removal of the eyes causes a cessation of secondary responses to illuminated background. Some melanophore activity remains. The cauterization of the optic chiasma or the infundibular stalk brings about the permanent expansion of the melanophores. Hypophysectomy, and cauterization with hypophysectomy, both produce permanent contraction of the melanophores. The implications of these results in relation to chromatic control are discussed.
The Influence of Dissolved Oxygen Concentration on the Toxicity of Potassium Cyanide to Rainbow Trout
Authors: Downing Kathleen M. 
Published: April 2021

ABSTRACT
Survival times of rainbow trout in concentrations of potassium cyanide in the range 0.105-0.155 p.p.m. cyanide increased with increase in dissolved oxygen concentration between 10 and 100 % of air saturation value, the effect being most marked with the lowest concentration of cyanide. The rate of increase of survival time with increasing concentration of oxygen did not appear to fall off as air saturation value was approached. The distributions of survival times which had median values of 3.3 min. or less were approximately normal, and those with median values of 13.0 min. or more were approximately log-normal.
The Activity of Slugs
Authors: Dainton Barbara H. 
Published: April 2021

ABSTRACT
Activity in slugs has been shown to occur in response to certain temperature changes (Dainton, 1954). In the description of these responses it was stated that light had no effect provided 1 hr. was allowed for light-adaptation. The experiments which led to this conclusion are described in this paper. Light initially stimulates activity in dark-adapted animals, but the response is short-lived, adaptation being complete within an hour. Preliminary observations indicated that activity was also affected by air currents, and responses to this form of stimulation are also described below.
Wallerian Degeneration in the Rat
Authors: Mannell W. A. , Rossiter R. J. 
Published: April 2021

ABSTRACT
If a peripheral nerve is cut, that portion of the nerve distal to the point of section undergoes a series of changes characteristic of Wallerian degeneration. Logan, Mannell & Rossiter (1952 a) showed that in the peripheral segment of the sciatic nerve of the cat degenerating after nerve section there is an increase in the concentration of nucleic acid. This change, which is probably related to the cellular proliferation that accompanies Wallerian degeneration, involves both pentosenucleic acid (PNA) and deoxypentosenucleic acid (DNA), although the increase in the two nucleic acids is disproportionate, resulting in an increase in the PNA/DNA ratio. Johnson, McNabb & Rossiter (1949 a) and Brante (1949) showed that there is also a later decrease in the concentration of myelin lipid, related to the destruction of the myelin sheath. Mannell (1952) reported similar changes for the sciatic nerve of the rat, although in this species all the processes are considerably speeded up in time.
The Respiratory and Glycolytic Enzymes of Sea-Urchin Eggs
Authors: Yčas Martynas 
Published: April 2021

ABSTRACT
A number of workers have studied the carbohydrate metabolism of sea-urchin eggs and have expressed different opinions about the pathway of carbohydrate breakdown in these eggs. The choice has rested between the breakdown of hexose via the ‘hexose monophosphate shunt’ and a glycolytic mechanism like that in yeast and muscle, followed by oxidation via the tricarboxylic acid cycle. Rothschild (1951) has summarized the evidence on this question. In listing the evidence in favour of the latter view, Rothschild included work reported in the author’s Ph.D. thesis (Yčas, 1950). Some of these results are presented in this paper. The evidence for a normal glycolytic and respiratory system has since been greatly extended by Cleland & Rothschild (1952a, b).
On The Drinking of Soil Capillary Water by Spiders
Authors: Parry D. A. 
Published: April 2021

ABSTRACT
A study has been made of the drinking of soil moisture by two species of lycosid spider. Carborundum powders have been used to provide a ‘soil’ of uniform particle size. The rate of drinking falls off with increase in the suction applied to the capillary water, finally becoming negligible, even though the soil remains saturated, at a suction which varies with the species of spider and possibly with the size of the individual. This limiting suction is never reached if the capillaries empty at a lower suction. The rate of drinking does not fall off with time, is similar for different individuals of the same species and size, and is not affected by soil particle size at a given suction, provided this is below the critical suction for the soil.
The Physiology of Sea-Urchin Spermatozoa
Authors: Rothschild Lord , Tyler A. 
Published: April 2021

ABSTRACT
The effect of adding sea water containing different concentrations of versene to suspensions of sea-urchin spermatozoa (Echinus esculentus) has been investigated, as regards their respiration, motility and fertilizing capacity. The respiratory Dilution Effect is progressively reduced and finally abolished when, instead of sea water, sea water containing 10−6, 10−5, 10−1 or 10−3 M versene is added to sperm suspensions. At the same time versene greatly delays the senescence of the spermatozoa, both as regards their motility and fertilizing capacity. For example, after seventeen hours, a 106 sperm/ml. suspension in sea water containing 10−3 M versene has 125 times the fertilizing capacity of a suspension containing 107 sperm/ml. without versene. The change in the ratio of seminal plasma to sea water which occurs when a dense suspension is diluted does not explain the Dilution Effect. These results are discussed in relation to the hypothesis which accounts for the Dilution Effect in terms of trace metals, particularly copper, normally occurring in sea water, and the amounts available per spermatozoon under various conditions of dilution.
A Physiological Interpretation of the Marching of Hoppers of the African Migratory Locust (Locusta Migratoria Migratorioides R. & F.)
Authors: Ellis Peggy E. , Hoyle G. 
Published: April 2021

ABSTRACT
Hoppers of the locust Locusta migratoria migratorioides R. & F., which have been reared crowded, exhibit characteristic marching behaviour in the laboratory in foodless cages under standard conditions. The rate of attainment of maximum marching by a given group of hoppers is greatest following a short period of starvation immediately preceding transfer to these conditions. A meal of filter-paper soaked in sugar solution only, exerts no retarding effectA physiological interpretation of marching hoppers 279 on the rate of attainment of full marching, whilst if an adequate concentration of potassium salt is added in addition a definite retardation is observed. In locusts actively feeding on grass the potassium content of the blood is relatively high, and it is suggested that this causes a reduced muscular efficiency which may explain retardation in attainment of full marching. The marching pattern is the result of the activity of particular nerve centres which require a period of activation by a combination of factors before full expression is achieved. Two final factors are essential for the maintenance of the marching state, a low concentration of blood potassium and mutual stimulation by other marching hoppers.
Observations on the Mechanism of the Opening of the Valves of A Burrowing Lamellibranch, Mya Arenaria
Authors: Trueman E. R. 
Published: April 2021

ABSTRACT
The ligament of Mya arenaria allows the valves to open normally and permits a rocking movement of the valves about a dorso-ventral axis to take place. This movement, which makes burrowing possible, is also associated with the divarication of the posterior end of the shell to allow the withdrawal of the siphon. A method of determining the resistance of various marine soils, ranging from clean sand to offshore mud, to the opening of the valves of M. arenaria is described. Even in the offshore mud, which is much less resistant than the sand, the opening moment of the ligament is approximately 6 times too small to cause the valves to gape. Records have been made of the opening of the valves of M. arenaria when loaded experimentally to varying degrees. A closing pattern of activity was observed with loads applied not exceeding the opening moment of the ligament, and with greater loads an opening pattern. The opening of the valves, in the latter instance, is found to be associated with a sudden increase in the water pressure in the mantle cavity. The increase in pressure is shown to be of the correct order of magnitude to open the valves of Mya in muddy sand by the application of a steady force. The liquefaction of the sand surrounding the lamellibranch, possibly by the expulsion of water through the pedal opening, would greatly facilitate the opening of the valves.
Fourth (Final) Report on A Test of McDougall’s Lamarckian Experiment on the Training of Rats
Authors: Agar W. E. , Drummond F. H. , Tiegs O. W. , Gunson M. M. 
Published: April 2021

ABSTRACT
This is the final report of an experiment of 20 years’ duration, in which we have repeated, in its essentials, the well-known experiment of William McDougall purporting to reveal a Lamarckian inheritance of the effects of training on rats. The test is one involving light discrimination, and McDougall recorded a steady improvement in the rate of learning on a succession of 32 generations; but he omitted to check the results against a properly conducted control.
Our experiment confirms McDougall to the extent that we too have obtained long duration trends of improvement in learning-rate (Figs. 2, 3); but we find that the effect is not sustained, and that it is, moreover, shown also by a control experiment, using animals of untrained ancestry. This forbids a Lamarckian interpretation.
Statistical analysis of the data indicates that the ‘condition’ of the rat markedly affects its speed of learning, and that progressive changes in learning-rate, over a succession of generations, are in reality correlated with the health of the laboratory colony, which is subject to periods of decline and recovery.
Water Balance in the Tick Ornithodoros Moubata Murray, with Particular Reference to the Influence of Carbon Dioxide on the Uptake and Loss of Water
Authors: Browning T. O. 
Published: April 2021

ABSTRACT
A study has been made of the exchanges of water between the atmosphere and the tick Ornithodoros moubata. Unfed nymphs are able to abstract water from moist air (95% R.H.) and to restrict their rate of water loss in dry air. This ability is lost (a) in atmospheres containing 30-45% CO2; (b) in atmospheres containing more than 90% N2 (c) immediately after the tick is fed; (d) gradually after the tick has been starved for some five months. It has been shown that the effect of high (30-45%) concentrations of CO2 is mainly upon the activity of the epidermal cells, possibly mediated through the central nervous system. The concentration required to cause opening of the spiracles is only about 5%.
Osmotic Responses in The Sipunculid Dendrostomum Zostericolum
Authors: Gross Warren J. 
Published: April 2021

ABSTRACT
The sipunculid Dendrostomum zostericolum demonstrates no ability to regulate osmotically. Dendrostomum behaves superficially as an osmometer, but is actually more complex: (a) the worm shows volume control in concentrated and dilute sea water; (b) it is permeable to salts, mostly through the gut and/or nephridiopores; (c) it can release osmotically active particles from its body wall to the blood. The body wall of Dendrostomum is highly permeable to water, but only slightly to salts. Permeability for both salts and water is greater inwards than outward. Dendrostomum can tolerate a loss of 36% body weight by desiccation and recover when returned to sea water. The mechanism of this tolerance appears to be the removal by fixation in the tissues, of osmotically active particles from the body fluids.
The Colour Change of the Minnow (Phoxinus Laevis Ag.)
Authors: Healey E. G. 
Published: April 2021

ABSTRACT
Minnows were subjected to spinal section at different levels between vertebrae 4 and 15, and the degree of dispersion of all the main melanophore regions was recorded in terms of the melanophore index. Records were made of the times required to reach equilibrium (a) when the fish were placed after the operation on a black or white illuminated background, and (b) when the fish at equilibrium on a black or white background were subjected to background reversal. These records show that the times necessary for the melanophores to reach equilibrium on a given background are of the same order at all the vertebral levels investigated. There is considerable variation in the degree of dispersion of similar melanophore regions of different individuals under the same conditions of operation and background. The nature of these individual differences is not known. Apart from the possibility of incomplete section of chromatic nerve fibres near the 15th vertebra, there appears to be no correlation between the chromatic behaviour and the level of the operation ; i.e. there is no indication that any activity of the spinal paling centre is being affected by spinal section at the different levels. The results of experiments involving the elimination of the spinal paling centre were tested statistically. Within the limits of this treatment, based upon the melanophore index, it was concluded that the spinal paling centre plays no part in these colour changes. Spinal section was carried out anterior to the 1st spinal nerve in order to interrupt the path of von Gelei’s dispersing fibres. Statistical treatment of the results indicates that these fibres are playing no part in these colour changes. Experiments involving combined spinal and autonomic section confirm the conclusions given in paragraphs 6 and 7. Since no activity of the nervous system arising from the spinal paling centre or resulting from the background through von Gelei’s dispersing fibres appears to be involved, the colour changes of these spinal minnows in response to illuminated backgrounds must be controlled by hormones alone. In these spinal fish the various melanophore regions do not all react equally in terms of the melanophore index. Thus, those of the lateral stripe and associated dark pattern tend to have relatively higher M.I. values under all conditions.