bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relationship of Oxygen Consumption to Age and Weight During the Post-Embryonic Growth of Locusta Migratoria L
Authors: Clarke Kenneth U. 
Published: April 2021

ABSTRACT
The weight and oxygen consumption of individual locusts, six from each instar, have been measured at 12-hourly intervals throughout each stadium.
An analysis of short duration changes shows that fluctuations in live weight are unavoidable in the growing animal, and that they are accompanied by fluctuations in oxygen consumption. In time the latter lag behind the former.
As the fluctuations of these two variables are out of phase, there is a considerable range of oxygen consumption which must be regarded as normal for any given weight. Calculations are made to find the limits of these fluctuations compatible with normal growth.
The changes that occur during a stadium can be represented by a straight trend line for both weight and oxygen consumption. Exceptions occur in the case of weight of the adult where two straight lines are necessary, one for the growing phase and one for the steady phase of this instar. In certain cases in the fifth instar two straight lines are necessary to express the trend in oxygen consumption which may show an abrupt change in the middle of the stadium.
A high degree of correlation is found between the trend lines for weight and oxygen consumption in the early instars. A low degree is found in latter instars where the weight increases and the oxygen consumption remains nearly constant.
A curve representing the changes of weight and oxygen consumption that occur during the growth of the locust has been constructed.
Temperature Tolerance and Acclimatization in Drosophila Subobscura
Authors: Smith J. Maynard 
Published: April 2021

ABSTRACT
The times for which adult Drosophila subobscura survived at high temperatures in dry and in saturated air were measured at different temperatures, over a range of survival times from 20 to 400 min. There is a linear relationship between the logarithm of the survival time and the temperature in both cases, the values of Q10 being approximately 350 in dry air and 10,000 in wet air. Survival times in dry air were increased in individuals previously kept at a high temperature (25° C.). Two kinds of acclimatization can take place, a long-lasting ‘developmental acclimatization’ in individuals kept at 25° C. during preadult life, and a transitory ‘physiological acclimatization’ in adults kept at 25° C. Survival times in saturated air were only slightly increased in individuals previously kept at 25° C. Although physiological acclimatization increased the resistance of flies to desiccation rather than to high temperature as such, it is nevertheless a response to previous exposure to high temperatures, and not to high saturation deficiencies. The reversibility of changes occurring at high temperatures was studied by exposing individuals for 50 min. to a temperature which would kill them in 100 min. and then retesting them after an intervening period at 20° C. Flies exposed to dry air recovered fully if they were allowed to drink ; flies exposed to saturated air recovered in 3 hr. at 20° C., but complete recovery in this period required the presence of food and water.
The Respiration of Helix Pomatia, A Balance Sheet
Authors: Kerkut G. A. , Laverack M. S. 
Published: April 2021

ABSTRACT
The respiratory rates of tissue slices from the various organs of Helix pomatia have been determined. The internal organs such as the brain and liver show a higher QO2 when immersed in Baldwin’s phosphate solution. The external organs such as the mantle and collar show a higher QO2 when immersed in Krebs-Ringer solution. The brain has the highest QO2; it is followed in order by the liver, gut, mantle, kidney, columella muscle, female duct, albuminous gland, body wall, dart sac and foot. The rate of respiration of a series of intact snails has been determined. The organs from each of these snails were removed, dried and weighed. From the respiration rates determined in the early part of the paper, a balance sheet was drawn up for each snail. The summated tissue respiration is compared with the respiration of the intact animal. In three out of the twelve cases cited there was good agreement between the summated tissue respiration and the respiration of the whole animal. In the nine other cases the respiration of the whole animal was 40-70% below the summated tissue respiration. This would indicate the possibility that the snail has some means of controlling the rate at which the tissues respire in the intact animal.
The Influence of Pigment Migration on Vision of Higher Crustacea
Authors: De Bruin G. H. P. , Crisp D. J. 
Published: April 2021

ABSTRACT
Exner believed that the movement of the distal pigment during light-adaptation improved the visual acuity of the superposition eye. This hypothesis was tested by measurement of the visual acuity of Leander serratus, Pandalus montagui and Praunus flexuosus under different conditions. When a dark-adapted animal is placed in the light the proximal pigment migrates into the light-adapted position more rapidly than the distal pigment. The distal pigment, but not the proximal pigment, undergoes diurnal rhythm and tends to migrate into the dark-adapted position at night, even when the animal is illuminated. The visual acuity may therefore be tested when the distal pigment is still in the dark-adapted position and the proximal pigment in the light-adapted position. No difference in visual acuity could be detected as a result of changes in the position of the distal pigment. Visual acuity increases and light sensitivity decreases when the dark proximal pigment migrates over the reflecting (tapetal) layer. Eupagurus bemhardus, which lacks the typical tapetum, shows no detectable change in visual acuity or sensitivity after being kept in the dark. These experiments do not support Exner’s view of the function of the distal pigment. They indicate that visual acuity is improved by the presence of the dark proximal pigment at the base of the proximal retinulae, probably because this pigment reduces stray reflexions from the back of the eye (halation). It is suggested that since the crystalline cones and crystalline tracts form optically continuous strands with a higher refractive index than that of the surrounding medium they may act as wave guides. If so they would retain light entering the corneal surface from sources close to the axis of the ommatidium, and so concentrate it on the rhabdomes and adjacent retinulae.
Effect of Anaesthetics on Workers of the Ant Myrmica
Authors: Weir J. S. 
Published: April 2021

ABSTRACT
Experiments have shown that ether, nitrous oxide, and carbon dioxide all have significant and different post-anaesthesial physiological effects on workers of Myrmica. They reduce longevity and all except nitrous oxide reduce oviposition. Nitrous oxide causes abnormally early accumulation of an egg mass. The effects of these three anaesthetics can be distinguished from one another, and from the effects of nitrogen anaesthesia (presumed anoxia). Their effects may occur together with, and in addition to, those attributable to anoxia. The effects of the anaesthetics on Myrmica longevity appear to be due to the direct physiological action of the anaesthetic and do not operate indirectly via ethological change as supposed in previous work on Apis. These results are discussed in relation to previous work including the concept of artificial ageing which is shown to be untenable in this instance.
Glucose Absorption in the Cockroach
Authors: Treherne J. E. 
Published: April 2021

ABSTRACT
The absorption of glucose from the gut of the cockroach has been studied by feeding starved insects with 14C-labelled glucose together with a dye, Amaranth. This dye is not absorbed from the lumen of the intestine and the net percentage glucose absorption has been calculated from the glucose/dye ratio in the various parts of the intestine. Glucose absorption is largely confined to the mid-gut caeca. The rate of crop emptying, which is an exponential function of time, is related to glucose concentration, so that the amount of fluid leaving the crop decreases with increasing concentration. This effect is determined by the osmotic pressure of the ingested fluid. The total glucose absorption shows a linear relation with crop emptying, suggesting that crop emptying is the limiting process in glucose absorption in the cockroach.
The Blood Volumes of Some Representative Molluscs*
Authors: Martin A. W. , Harrison F. M. , Huston M. J. , Stewart D. M. 
Published: April 2021

ABSTRACT
The reports of measurements of the blood volume of molluscs found in the literature are few in number and represent, in most cases, incidental observations rather than results of specific investigations. Leitch (1916) obtained by the bleeding of Planorbis a volume of blood which was 33% of the tissue weight. In 1931, Borden determined the blood volume of Planorbis corneus using the Weicker method and obtained a value of 58% of the total tissue weight. This higher value is to be expected, since it is impossible to remove all the blood from an animal by simple bleeding. In 1950, Martin & Huston, using the inulin dilution method, reported the blood volume of Aplysia californicus to be 83·3% of the total weight. This is not surprising since Aplysia has a very extensive haemocoele, and more than half the body weight in blood can be drained in a few minutes from a single incision into the animal.
In Vitro Culture of Embryos in the Silkworm, Bombyx Mori L
Authors: Takami Takeo 
Published: April 2021

ABSTRACT
It is generally believed that the diapausing egg of the silkworm contains a substance which is transmitted from the mother and has an inhibitory action upon the development of the embryo. Watanabe (1924) was the first author to explain the phenomenon of diapause in the silkworm egg by postulating this substance which he called ‘inhibitory substance’, and almost all subsequent authors in Japan have accepted this assumption. It is not unreasonable to suppose that the ‘inhibitory substance’, which reveals its action in the egg after deposition, has some connexion with the diapause factor (hormone) secreted by the suboesophageal ganglion of the mother (Hasegawa, 1951, 1952; Fukuda, 1951), but nothing is known about the real nature and action of the diapause factor (Fukuda, 1955).
The Absorption of Glucose from the Alimentary Canal of the Locust Schistocerca Gregaria (Forsk.)
Authors: Treherne J. E. 
Published: April 2021

ABSTRACT
The absorption of glucose from the alimentary canal of Schistocerca gregaria has been studied by filling the gut with a saline solution containing 14C-labelled glucose together with a dye, Amaranth, which was used as a marker. The net percentage absorption was calculated from the glucose/dye ratio in the various parts of the alimentary canal. The bulk of the glucose was absorbed from the mid-gut caeca, smaller amounts being absorbed by the ventriculus. Glucose absorption was studied at concentrations of 0·002, 0·02 and 0·20 M/1. in solutions in which the total osmolarity was maintained by altering the NaCl concentration. The percentage absorption was similar at concentrations of 0·002 and 0·02M/1., but was significantly less at 0·20M/1. The fate of the 14C-labelled glucose was followed using paper chromatography. The glucose was shown to be rapidly converted to trehalose in the haemolymph. At a concentration of 0·20M/1. this mechanism became saturated and excess glucose accumulated in the haemolymph. The absorption of glucose in vitro, from a gut suspended in a relatively large volume of poisoned saline, was found to be similar to that in the intact insect. From these observations it is suggested that glucose is absorbed by diffusion across the gut wall and that the process is facilitated by the rapid conversion of glucose to trehalose in the haemolymph, which tends to maintain a steep concentration gradient across the gut wall.
Seasonal Variation in the Respiratory Acclimatization of the Leech Erpobdella Testacea (Sav.)
Authors: Mann K. H. 
Published: April 2021

ABSTRACT
In a preliminary study of the oxygen consumption of leeches (Mann, 1956), it was shown that Erpobdella testacea has an oxygen consumption which is independent of the oxygen concentration in the water, over the range 2–6 ml./l., provided that it has been acclimatized overnight to the oxygen concentration of the experiment. The determinations in these experiments were made by enclosing the leeches in glass-stoppered bottles for periods of about 1 hr. Such experiments are unsatisfactory for a study of acclimatization because: (i) the oxygen concentration is constantly changing, (ii) the duration of the experiments is limited, and (iii) the closing of the bottles and the shaking which is necessary to ensure proper mixing of the water make it difficult to keep the animals in a quiescent state. An apparatus was therefore devised to enable the animals to be placed in a slow stream of water of any desired constant oxygen content, so that their oxygen consumption could be measured over a period of days. In this way it was possible to obtain a true resting state, and to investigate acclimatization in differing oxygen concentrations at different times of year.
The Influence of Preoperational Training On the Performance of Octopuses Following Vertical Lobe Removal
Authors: Wells M. J. , Wells J. 
Published: April 2021

ABSTRACT
Blind octopuses were trained to discriminate between two objects by touch by taking one and rejecting the other. When they had learned to do this their vertical lobes were removed and postoperational survival of the effects of preoperational training was tested, either by continuation of training or by means of retention tests. When training was continued after vertical lobe removal animals pretrained at a rate of 8 trials per day for 48 or 96 trials reverted to taking both of the objects to be discriminated (as at the start of training), but subsequently relearned to dis-criminate between them with an accuracy approaching that of controls. They took fewer trials to learn after operation than animals that had not been pretrained. Animals pretrained at a rate of 40 trials per day for 120 trials showed little or no disturbance of learned responses as a result of the same operation. In retention tests carried out immediately after operation, animals pretrained for a similar number of trials at rates of 8 and 40 trials per day made more errors than controls, but showed, nevertheless, that the effects of pretraining by either method were not entirely lost as a result of the operation. These results are discussed in relation to the general problem of the interpretation of discrimination experiments which force animals to react ‘positively’ or ‘negatively’ in an all-or-nothing manner and thereby conceal differences in the degree to which memories are established. It is concluded that the effect of vertical lobe removal can be attributed to a reduction in the amount of tissue available for memory retention.
The Oxygen Dissociation and Alkaline Denaturation of Haemoglobins from Two Species of Earthworm
Authors: Haughton T. M. , Kerkut G. A. , Munday K. A. 
Published: April 2021

ABSTRACT
A method is described for determination of the oxygen dissociation curves of the blood of two species of earthworm, Lumbricus terrestris and Allolobophora terrestris. The following values have been obtained for the partial pressures of oxygen (mm. Hg) required to saturate the blood: Times for alkaline denaturation at pH 12·7 have been found as follows: Lumbricus terrestris 23 min., L. rubelhis 2·5 min., L. festivus 11·5 min., Allolobophora terrestris 6 min., Eisenia foetida 5 min. These results indicate definite differences in the properties of the haemoglobin of the species examined.
Ionic Fluxes in Artemia Salina (L.)
Authors: Croghan P. C. 
Published: April 2021

ABSTRACT
The ionic fluxes between the medium and haemolymph have been studied in adult Artemia salina, under steady-state conditions using 24Na and 82Br. Extremely high fluxes have been found, the flux increasing markedly in the more concentrated media. The results are interpreted as indicating that both the sodium and chloride in the haemolymph are undergoing rapid exchange diffusion with the sodium and chloride in the medium.
The Mechanism of Object Location in Gymnarchus Niloticus and Similar Fish
Authors: Lissmann H. W. , Machin K. E. 
Published: April 2021

ABSTRACT
Experiments with moving electrostatic and magnetic fields show that Gymnarchus niloticus is sensitive to a potential gradient of about 0 · 03 µ V./cm. Alternative explanations of some previous experiments are given in terms of this high d.c. sensitivity. An explanation in similar terms is given of experiments in which Gymnotus carapo is trained to detect a stationary magnet. The mechanisms available for the location of objects by electric fish are reviewed. It is concluded from the results of a critical experiment (described in a succeeding section) that Gymnarchus niloticus can detect objects by the disturbance of its own electric field in the water. The approximate theory of this method of object location is derived. The effect on the receptors of the perturbing field due to an object depends on the electrical properties of the receptors: in the extreme cases the stimulation of the receptors is proportional either to the potential or to its second derivative. Graphs are given showing the effect of an object on the potential and on its second derivative around the surface of the fish. Experiments are described using Gymnarchus niloticus which (a) confirm that the mechanism of object location employs electric field distortion ; (i) indicate the limits of the sensitivity of the fish. The second derivative mode appears to be the most probable one operating in Gymnarchus. The experimentally determined limits of detection are discussed in relation to the random noise in the receptor circuit : it is concluded that both spatial and temporal integration are likely to be employed. The thresholds for object location and for response to direct currents are compared : it is concluded that the same receptors are probably operating in both cases.
Ionic Regulation in the Brown Trout (Salmo Trutta L.)
Authors: Gordon Malcolm S. 
Published: April 2021

ABSTRACT
The osmotic and ionic regulatory abilities of adults of the euryhaline brown trout (Salmo trutta) have been studied in experiments roughly duplicating the stresses of migration from fresh water to the sea. Brown trout will survive indefinitely in full sea water if acclimatized to it at rates inversely related to the temperature. Blood serum samples have been analysed for Na, K, Cl, total P and Δ; muscle samples for Na, K, Cl and total solids. Changes in the concentrations of these constituents following transfers from fresh water to 50% and 100% sea water have been studied. Transfers were made throughout the year and at temperatures of 10° C. and 20°C. Following transfers to 50% sea water at 20° C. blood concentrations rose significantly above fresh-water levels, but returned very nearly to these levels after about a week. Transfer from 50% sea water to 100% sea water at 20°C. caused the same sequence of changes. Transfer to 100% sea water at 20° C. was fatal, and associated with very high serum concentrations. Many fish survived transfer to 100% sea water at 10° C., however, and showed evidence of internal concentrations returning to fresh-water levels after 10 days. The brown trout is strongly homoiosmotic on a long-term basis. Both survival and regulatory ability were lower during the summer. There were also seasonal variations in the blood and muscle concentrations of fish in a given state of acclimatization. Muscle concentration changes closely paralleled blood changes. Extracellular volume remained constant, so muscle concentration changes were attributable to changes in intracellular water. The muscles did not act as storage sites for sodium and potassium.
Studies On the Shoaling Behaviour of Fish
Authors: Steven D. M. 
Published: April 2021

ABSTRACT
Hepsitia stipes and Bathystoma rimator swim in shoals during the day but disperse at night. The fish become increasingly active as illumination decreases and shoals begin to disperse when it falls below about 0·1 f.c. The change from day to night patterns of behaviour is progressive; there is no sudden switch from one to the other at any single level of illumination. Exploratory feeding behaviour similar to normal nocturnal activity can be induced during the daytime by olfactory stimuli. When so stimulated the average swimming speed is about twice as fast as in unactivated fish. Aqueous extracts of mammalian tissues, of marine animals and water in which live plankton has been kept evoke exploratory feeding behaviour. Fish so stimulated attack live plankton which they can see but not reach and will pick up and sometimes swallow pieces of filter-paper which they had previously ignored. The substance in the adductor muscle of Area zebra that excites exploratory feeding behaviour is dialysable and unaffected by boiling. It is effective in concentrations of the order of 1 × 10− 9. Fish can detect trace amounts of many organic substances, to a few of which they respond in a way similar to exploratory feeding, though of less intensity and shorter duration than is the case with extracts of natural food substances. Blinded Bathystoma respond to extracts of Area muscle with a modified type of exploratory feeding behaviour and can locate the position of pieces of food. These experiments are discussed in relation to the behaviour of fish shoals in the sea.
The Composition of the Blood of the Shore Crab, Carcinus Moenas Pennant, in Relation to Sex and Body Size
Authors: Gilbert A. B. 
Published: April 2021

ABSTRACT
The influence of sex and body weight on the concentration of sulphate and chloride ions in the blood of the common shore crab was investigated. Blood chloride increased in both sexes until a maximum was reached at a weight of about 35 g.; thereafter it fell with increasing body weight. Over the whole size range blood chloride was higher in females than in males. This difference was highly significant for animals over 35 g. body weight; below 35 g. however, there was no significant difference between the sexes. Over a restricted size range blood sulphate of males was significantly higher than that of females. Results of the present work have been discussed in relation to those reported earlier for conductivity and total O.P.
The Cuticle ofAcarus SiroL. (=Tyroglyphus Farinae)
Authors: Hughes T. E. 
Published: April 2021

ABSTRACTThe thin cuticle of Acarus siro contains a relatively large quantity of sulphur. The sulphur does not form disulphide linkages between cysteine molecules as it does in keratin. The presence of lysine amongst the products of hydrolysis shows that this cuticle is not tanned by linkage of quinone and amino groups. The experimental data support the view that the cuticle is tanned by reaction of quinones and sulphydryl groups. It is suggested that the quinone involved is a paraquinone, probably derived from phenylalanine.
The Responses of Snails to Polarized Light*†
Authors: Baylor Edward R. 
Published: April 2021

ABSTRACT
Experiments were performed to test whether the polarized light responses of the marine snail, Nassa obsoleta, are mediated by a polarizing analyser within the eye or by the pattern of intensities reflected from the substratum. Snails able to see only the substratum orient at right angles to the plane of vibration of vertically incident polarized light. Snails unable to see the substratum but able to see the overhead source of polarized light fail to orient to the polarized light Implications regarding the rare occurrence of intra-ocular polarizing analysers and the improbability of extensive animal use of polarized light as a navigational aid are discussed.