bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phases of Activity in the Sea-Anemone,Metridium Senile(L.), and Their Relation to External Stimuli
Authors: Batham E. J. , Pantin C. F. A. 
Published: April 2021

ABSTRACTWe have shown in a previous paper (Batham & Pantin, 1950b) that the sea-anemone Metridium senile exhibits continual very slow muscular activity. It is most evident in the changes of shape of the column caused by the reciprocal contractions of the circular muscle sheet, and of the longitudinal parietal musculature which runs at the junction of each mesentery with the body wall. This inherent activity varies, so that in the same individual it presents a different pattern on different occasions. The pattern may remain constant for hours on end, and may then change over a comparatively short period. Thus a moderately filled anemone giving fairly regular and substantial contractions may pass into a condition with a larger volume and much less apparent activity, or it may pass into a condition of prolonged and almost complete contraction. These patterns of activity often endure for long periods—hours or even days. It is convenient to refer to such patterns as ‘phases’, and these phases form the subject of this paper.
The Influence of Water and Light Upon the Pigmentary System in the Common Frog Rana Temporaria
Authors: Rowlands Anne 
Published: April 2021

ABSTRACT
A significant influence of water in relation to colour change in Rana temporaria has been established. Its action on the melanophores in relation to background shows it exerts an independent influence. Thus (a) with a black illuminated environment, water accentuates the background response, (b) with a white illuminated environment there is antagonism, (c) in darkness the presence of water induces extreme expansion, and drying induces contraction, but only after prolonged periods. Immersion on a white illuminated background causes immediate expansion, and prolonged drying even upon a black background induces contraction. During the breeding cycle, the males fail to darken when immersed upon a white illuminated background. This particular seasonal effect is not shown by the females. It was further shown that the water response is independent of the primary response. The greater the degree of immersion, the greater the degree of expansion maintained upon a white illuminated background, so that the area of contact is significant, and it is highly probable that skin receptors are concerned. The lower oxygen tension of water as compared with that of the atmosphere was not a significant factor in the expansion of the melanophores due to immersion.
The Integration of Activity Cycles in the Behaviour of Arenicola Marina L
Authors: Wells G. P. , Albrecht Elinor B. 
Published: April 2021

ABSTRACT
The common lugworm exhibits two distinct types of spontaneous activity cycle. Each of them has been described in some detail, but the method of approach was rather different in the two cases, and their integration has not yet been discussed. The experiments to be described were made to throw light on their mutual relations. The work was done at the laboratory of the Marine Biological Association of the United Kingdom, at Plymouth, in March and April 1950.
The relevant features of the two cycles, as hitherto described, will first be summarized. For a more detailed review see Wells (1950).
The Role of Oesophageal Rhythms in the Behaviour of Arenicola Ecaudata Johnston
Authors: Wells G. P. , Albrecht Elinor B. 
Published: April 2021

ABSTRACT
The British fauna includes three species of Arenicola. The most abundant is the common lugworm, A. marina L., which Uves in great numbers on tidal sand flats and mud flats. The other two, A. ecaudata Johnston and A. branchialis Aud. & Edw. (=A. grubii Claparède), are found, usually together, in. coarse, rather foul, sandy material, between stones and rocks.
The Temperature-Pulse Rate Curve of the Isolated Frog’s Heart (Rana Temporaria)
Authors: Smith C. L. 
Published: April 2021

ABSTRACT
A seasonal difference in the temperature-pulse rate curve of the isolated frog’s heart was described by Barcroft & Izquierdo (1931). In the summer they found an almost linear relation between temperature and frequency of pulsation from 5 to 20° C., while in the winter the relation was exponential over the same temperature range. Carter (1933) investigated the effects of various endocrine and related substances on the form of the temperature-pulse rate curve. He found that the addition of thyroxine to the medium perfusing the heart transformed the curve given by the winter heart into the summer form, but had no effect on that of the summer heart. He concluded that the seasonal change in the temperature effect on heart rate was controlled by the endocrine system, and that the thyroid by increase in its activity in the summer was the effective agent.
Studies in Diurnal Rhythms I. Rhythmic Behaviour in Millipedes
Authors: Cloudsley-Thompson J. L. 
Published: April 2021

ABSTRACT
Visual experiments on two small British species of millipedes have demonstrated that the diurnal cycle of rhythmic activity as represented by the number of animals on the surface is primarily a response to light and darkness, but is also correlated with the stimulus of falling temperature in the evening.
Aktograph experiments on two large West African species of millipedes have demonstrated an endogenous diurnal rhythm independent of fluctuating light and temperature, and persisting (in Ophistreptus) up to 19 days. Locomotory activity is stimulated both by increases and decreases of temperature; and it is probable that temperature fluctuations are of primary importance in the initiation of diurnal rhythms. The effect of light on activity is slight, but constant temperatures over long periods have, a depressing effect.
The Effect of Carbon Dioxide and Certain Respiratory Inhibitors on the Respiration of Larvae of the Horse Bot Fly (Gastrophilus Intestinalis De Geer)
Authors: Levenbook L. 
Published: April 2021

ABSTRACT
In a previous paper (Levenbook, 1950a) it has been demonstrated that the larvae of the fly Gastrophilus intestinalis de Geer, parasitic in the stomach of the horse, contain far more carbon dioxide in their haemolymph and tissues than is normally found in insects, and that this is a consequence of the extremely high CO2 tension prevailing in their normal habitat. In the present study it will be shown that these larvae are so adapted to CO2 in their environment that its removal leads to a profound depression of their respiration and to eventual death.
The Physiology of Contractile Vacuoles
Authors: Kitching J. A. 
Published: April 2021

ABSTRACT
Evidence from osmotic experiments indicates that the amount of osmotically inactive material in the suctorian Podophrya is small, and that the internal osmotic pressure of the cytoplasm is approximately that of a 0·04 M solution of non-electrolyte. When the internal osmotic pressure of Podophrya is raised to an abnormally high level by equilibration with a solution of ethylene glycol or with dilute sea water, and the organism is then transferred to tap water, the rate of vacuolar output is temporarily raised far above its normal value. The body swells only slightly. This is taken as good evidence for osmoregulation. When Podophrya is placed in a dilute solution of sucrose the rate of vacuolar output (relative to the original rate in tap water) decreases rectilinearly with the concentration of sucrose used, reaching zero at about 0·04 M. This is as would be required for good osmoregulation. There is a slight lag in the response of the contractile vacuole to a change of medium. It is suggested that this delay in adjustment of the osmoregulatory mechanism must result in a slight change of body volume, which could be the basis for the control of vacuolar output.
Wave-Riding Dolphins*
Authors: Woodcock A. H. , Mcbride A. F. 
Published: April 2021

ABSTRACT
In an effort to explain the apparent ability of dolphins to ride the bow wave of a ship at a speed of 10 knots (Woodcock, 1948) it seemed necessary to show that the animals had weight while immersed. Measurements of the weight of an immersed Stenella plagiodon have been made.‡ First results indicate that a dead animal, which weighs 200 lb. in air, and is 6·5 ft. long, weighs 9·2 lb. when immersed in sea water. This animal, which was in good physical condition, was killed by injection just before the weighings were made.
Aerodynamics of Flapping Flight With Application to Insects
Authors: Osborne M. F. M. 
Published: April 2021

ABSTRACT
General formulae are derived giving the lift, thrust and power when the wing motion is specified. The formulae are applied to twenty-five insects for which quantitative data are available. Average values for lift and drag coefficients, CL and CD, are derived by equating the weight to the vertical force and the thrust to the horizontal drag of the body. The large drag and lift coefficients obtained for insect flight are attributed to acceleration effects. There is a distinct correlation between and the ratio of the flapping velocity of the wings to the linear velocity of flight. When this ratio and therefore the accelerations are small, the force coefficients do not exceed those to be expected for flat plates. Owing to the nature of the assumptions and approximations made, the values derived for CD, CL and CD/CL are minimum values. Other characteristics of insect flight are discussed. In general, insects fly in such a way as to minimize the mechanical power required. In most, but not all cases, the useful force is the one perpendicular rather than parallel to the relative wind. The wing tips should move in a figure 8, the down beat should be slower than the up beat, and the majority of the necessary force must be supplied on the down beat. Figures are given using the data from the twenty-five insects considered, showing average relations between power, specific power, mass, acceleration forces, force coefficients and geometrical dimensions. The power per gram, the ‘wasted power’, and the force coefficients all increase as the importance of the acceleration forces increases. When plotted as functions of mass, quantities involving the power show much less dispersion than quantities involving the geometrical dimensions. This is taken to mean that despite the diversity of insect form, as ‘power plants’, they are all essentially similar. A table of the observed or adopted flight parameters (frequency of beating, mass, wing area, velocity of flight, amplitude and orientation of wing motion) is appended.
The Reactions of the Minnow, Phoxinus Phoxinus (L.), to Solutions of Phenol, Ortho-Cresol and Para-Cresol
Authors: Jones J. R. Erichsen 
Published: April 2021

ABSTRACT
This paper records some observations on the reactions of minnows to phenolic substances. The fish are placed in a horizontal tube, half of which is filled with flowing water and half with flowing solution of the concentration to be tested. Water and solution are very sharply differentiated.
Solutions of phenol, ortho- and para-cresol are highly toxic and appear to have some specific effect on the nervous system of fish, causing them to lose their sense of balance and capability of co-ordinated movement. The time the solutions take to produce this effect is much shorter than the survival time; in a 0.01% solution of para-cresol, for example, a minnow loses its sense of balance in about 70 sec. but takes about 30 min. to die.
Over the concentration range 0.04-0.0004% minnows appear to have little or no power of discriminating between phenol and water, swim into the solution and become intoxicated.
At concentrations of 0.03-0.04% minnows will avoid para-cresol and ortho-cresol solutions immediately and escape intoxication. At somewhat lower concentrations the fish venture into the solution, and this quickly destroys their capability of recognizing and avoiding it. The situation is markedly different from that observed in the case of lead and zinc salts; here the time the fish takes to establish an avoiding reaction to the solution is very much shorter than the time this takes to destroy its capability of doing so.
Cell Number in Haploid, Diploid and Polyploid Mouse Embryos
Authors: Beatty R. A. , Fischberg M. 
Published: April 2021

ABSTRACT
Cell number, determined by counting the nuclei, has been studied in preimplantation haploid, diploid, triploid, tetrapioid and hexapioid eggs of Mus musculus, recovered usually days after fertilization. Most of the data concern triploid and tetrapioid eggs, from the early morula to late blastula stages. The mean number of cells in polyploid eggs (and perhaps in haploids), relative to the number in diploids of the same age, is approximately in inverse proportion to the number of chromosome sets present. Thus, the ratio of cell number in polyploid eggs to cell number in diploid eggs decreases with an increase in the number of chromosome sets. There was no evidence for any one type of heteroploidy that the différences in ratios encountered from mouse to mouse were due to anything other than sampling error, i.e. the ratios remained fairly constant from the early morula to the late blastula. This suggests that the lesser number of cells in polyploids is already apparent in early cleavage. These findings are compared with the parallel situation in Amphibia. The counting of nuclei can play a role, but only a limited one, in the identification of polyploid eggs.
The Influence of Water and Light Upon the Colour Change of Sightless Frogs (Rana Temporaria)
Authors: Rowlands Anne 
Published: April 2021

ABSTRACT
Cauterization of the region of the optic chiasma causes the permanent expansion of the melanophores. Subsequent cauterization of the eye has no further effect. Severance of the optic nerve or damage to the eye itself results in the cessation of the chromatic response to illumination and background. Specimens operated upon in this manner do not lose the melanophore response to moisture, contracting in dry and expanding in moist conditions. Only a slight residual primary response can be detected. The implications of these results in relation to chromatic control are discussed.
Fermentation in the Rumen of the Sheep
Authors: Gray F. V. , Pilgrim A. F. 
Published: April 2021

ABSTRACT
A previous communication in this series of papers (Gray, Pilgrim & Weller, 1951) gave an account of the fermentation of wheaten hay and lucerne hay by organisms from the rumen of the sheep, in which the overall production of each of the main volatile fatty acids was determined. In view of the complex nature of both the substrate and the mixed population of organisms involved, it was decided to investigate the intermediate stages of the fermentation to determine whether any important changes take place in the composition or in the rate of production of the mixture of acids.
The Swimbladder and the Vertical Movements of Teleostean Fishes
Authors: Jones F. R. Harden 
Published: April 2021

ABSTRACT
Perch can only swim freely above their plane of equilibrium within a narrow zone whose height is equivalent to a 16% (one-sixth) reduction in the total pressure to which they are adapted. Excursions from this zone would not involve more than a 33 % reduction of the total pressure. Calculations were made of the minimum time in which perch could make slow vertical movements involving reductions of 10-90% in the total pressure to which they were originally adapted, and it was concluded that perch would not make diurnal migrations in which the reduction was more than 40% of the total pressure. It is unlikely that teleosts with closed swimbladders would be able to make diurnal migrations as extensive and rapid as that shown by the deep scattering layer unless the swimbladder was reduced in size, the bladder wall thickened to resist expansion of the gas, or the rate of gas resorption 20-30 times quicker than in the perch.
Pharmacological Investigation of the Nature of the Innervation of the Muscles of Helix Aspersa
Authors: Graham Jas. D. P. , Heathcote R. St A. 
Published: April 2021

ABSTRACT
Bacq (1947) has reviewed the known actions of autonomic effector substances on invertebrates. Concerning the muscles of snails relatively little is known. Boyer (1926) showed that adrenaline had no effect on the contraction of the ventricular muscle of Helix pomatia in a concentration of less than 1 in 20,000, but that higher concentrations slowed the heart and produced irregularities of rhythm. Very high concentrations (1 in 250) arrested the heart beat. According to Jullien (1936) the ventricle of the same snail is sensitive to acetylcholine in a concentration of 1 part per million. There seems to be little other information available, other than the general statements of Bacq (1947) that in many Molluscs physostigmine (eserine) fails to potentiate the effects of acetylcholine, that in Cephalopods curare, but not atropine, abolishes the effect of stimulating the vesical nerve, and that in Molluscs as a whole the muscles of locomotion do not appear to be cholinergic in type.
In the common English snail, Helix aspersa, a portion of the alimentary canal (crop and rectum), or of the heart (ventricle), or the columellar muscle (which retracts the main part of the snail within its shell) was isolated, and the effects of drugs upon it examined, with the aim of determining the nature of the neurohormonal mechanism involved in contraction.
Studies on Tapeworm Physiology
Authors: Smyth J. D. 
Published: April 2021

ABSTRACT
Plerocercoid larva of the cestode Schistocephalus solidus were cultured in vitro in horse serum + 1 % glucose at the following temperatures: 35, 34, 33 and 30° C. ; the temperature at which maturation normally takes place being 40° C. Eggs capable of embryonation were never produced by larvae cultured at a temperature less than 35° C. Below this temperature, spermatogenesis became markedly abnormal, resulting in the production of polyploid cells and degenerating spermatid morula. No abnormalities in the vitellaria or ovaries were observed at these subnormal temperatures.
The Action of the Proventriculus of the Worker Honeybee, APIS MELLIFERA L
Authors: Bailey L. 
Published: April 2021

ABSTRACT
The proventriculus of the worker honeybee is an organ which effects a highly efficient separation of pollen grains from the medium in which they are suspended. The pollen grains are packed tightly together by the proventriculus and are passed as a bolus down to the ventriculus. The boluses pass quite quickly towards the posterior end of the ventriculus (5–20 min.), depending on the concentration and amount of pollen suspension which is fed. The peritrophic membranes do not move down the ventriculus with these packages but pass down at a slower rate. At the posterior end of the ventriculus the pollen may be held up for a considerable time. In the brood-rearing bee it stays there for many hours (up to 12 or more). In the forager it begins to pass down the hindgut to the rectum after 3 hr. or less. The volume of fluid within the honey stomach, the size of particles in suspension and their concentration have significant effects on the rate and efficiency of filtration by the proventriculus. Some reflexions are made on the possible physiological significance of the mechanism of the proventriculus to the worker honeybee.
The Relationship of Carbohydrate Metabolism and Mitotic Activity in the Mouse
Authors: Laws John O. 
Published: April 2021

ABSTRACTIn recent years much interest has been shown in the biochemistry of mitosis, both as regards the process itself and the agents capable of controlling the frequency of its occurrence in the tissues. This interest has originated in two groups of workers, those biologists who are interested in the fundamental problems of growth and cell division, and the cancer workers who hope, by further understanding these processes, to be able to control the abnormal growth exhibited by tumours.
The Reactions of Fish to Water of Low Oxygen Concentration
Authors: Jones J. R. Erichsen 
Published: April 2021

ABSTRACT
This paper presents the results of about 100 experiments to test the reactions of small fish to water of low oxygen concentration, using an apparatus similar to that previously employed by the writer to study the reactions of fish to toxic solutions. At 13 ° C. the stickleback (Gasterosteos acoleatos) has no immediate appreciation of water of low oxygen concentration and will swim into it with no hesitation. If the fish remains in the poorly oxygenated water respiratory distress develops, accompanied by uneasiness and random movement. When this random movement takes the animal back into the well-oxygenated water the stimulus to swimming vanishes, the fish stops moving and quickly recovers. Over a wide concentration range at 13 ° C. the reaction takes 1 · 3 min. At 3 ° C. the reaction is very slow, taking 5-6 min. even when the water contains only 0 · 3 mg./l. of oxygen. At 20 ° C. and oxygen concentrations below 2 mg./l. the response is very prompt, respiratory distress developing so quickly that the fish usually will not swim into the poorly oxygenated water, but turns away from it or swims backwards; it may make repeated attempts to enter the low-oxygen zone, retreating each time as if violently irritated. Experiments with minnows (Phoxinus phoxinus’) and trout fry (Salmo truttà) gave generally similar results. Here again the essential factor appears to be the speed with which dyspnoea develops.
The Metabolism of the Sea-Urchin Egg
Authors: Cleland K. W. , Rothschild Lord 
Published: April 2021

ABSTRACT
The endogenous O2 uptake of sea-urchin egg homogenates (Echinus esculentus) was inhibited by malonate, fluoride, iodoacetate, and fluoracetate. The addition of the tricarboxylic acid cycle intermediates, citrate, a-keto-glutarate, succinate, fumarate, malate, and glutamate stimulated O2 uptake. The efficiency of the pyruvate-oxidizing mechanism varied in different preparations, but in some, added pyruvate was completely oxidized. (1)-(3) strongly suggest the presence of a tricarboxylic acid cycle. Glycogen, glucose and fructose stimulated O2 uptake. The oxidation of fructose was stimulated by DPN and inhibited by fluoride and iodoacetate. Glucose-1-phosphate, glucose-6-phosphate, fructose-6-phosphate and fruc-tose-i :6 diphosphate stimulated O2 uptake. Phosphogluconate also stimulated O2 uptake, which suggests that the enzymes of the hexose monophosphate shunt system may be present. The experiments described in this paper show that the principal pathway by which carbohydrate is broken down is the normal glycolytic one.