bluuebunny/crossref_metadata_2025_split huggingface dataset:
Excitatory and Inhibitory Pathways in the Arm of Octopus
Authors: Fraser Rowell C. H. 
Published: April 2021

ABSTRACT
The octopus is an exceptionally strong, active and manipulative animal. The structure of the arms enables the animal to move over any sort of terrain, to apply a formidable grip or pull, to make most delicate movements, such as picking at tight knots in wet cotton until they loosen, to reach and clean any part of the body, or to make delicate sensory discriminations. The great learning ability of Octopus was first shown for visual problems by Young and Boycott and their school, but Wells and Wells have subsequently shown an equal ability to deal with tactile information from the arms (see Wells (1962) for reviews). The arms contain a large part of the central nervous tissue of the animal, with intrinsic sensory, interneural and motor elements, possess organized reflex systems, and are capable of quite a lot of autonomy. It is thus good material in which to study the lower organization of an invertebrate central nervous system.
Influence of Neurosecretory Cells and of Corpus Allatum On Intestinal Protease Activity in the Adult Calliphora Erythrocephala Meig
Authors: Thomsen Ellen , Møller Ib 
Published: April 2021

ABSTRACT
The protease activity of the adult Calliphora female measured on the first 5 days after emergence was found to be highly influenced by the diet, the activity of females fed on sugar, water and meat (meat-flies) being much higher than that of females fed only on sugar and water (sugar-flies). The development of the enzyme(s) was found to be controlled by the medial neurosecretory cells (m.n.c.), the mean protease activity of females deprived of their m.n.c. only amounting to one-quarter to one-third of the maximum values for the meat-flies. Implantation of corpora cardiaca-allata (presumably containing m.n.c. hormone) into females without m.n.c. raised the protease activity of these significantly, showing that the influence of the implanted organs must be hormonal. The corpus allatum was found to have a certain, if minor, effect on the protease activity. It is concluded that in Calliphora the eating of meat exerts its effect on the production of protease mainly indirectly by causing liberation of m.n.c. hormone into the blood. As proteases are themselves proteins, the effect of the m.n.c. hormone on the production of proteolytic enzymes by the gut cells must be regarded as an effect on the specific protein synthesis of these cells. There is some evidence that the m.n.c. hormone might be involved in the regulation of protein synthesis in general.
The Possible Involvement of An Amino Acid Decarboxylase in the Stimulation of the Pericardial Cells of Periplaneta by the Corpus Cardiacum
Authors: Davey K. G. 
Published: April 2021

ABSTRACT
Semicarbazide hydrochloride and isonicotinic acid hydrazide, which are both inhibitors of phosphopyridoxal-dependent systems, inhibit the increase in the rate of beating of hearts which is brought about by breis of corpora cardiaca. This inhibition is partially reversed by phosphopyridoxal. Semicarbazide decreases the percentage of argentaffin-positive cells among pericardial cells exposed to breis of corpora cardiaca. DOPA increases the rate of beating of the isolated heart. This increase is mediated by the pericardial cells and is inhibited by semicarbazide. The inhibition by semicarbazide is reversed by phosphopyridoxal. It is suggested, as a working hypothesis, that the hormone from the corpus cardiacum stimulates the pericardial cells to produce an amine from an amino acid by the action of the appropriate amino acid decarboxylase. The hormone intervenes either by causing the cells to produce more of the amino acid, or by unmasking the amino acid which is pictured as being protected from the enzyme in the unstimulated cell.
Co-Ordination of Successive Activities in An Aphid. the Effect of Flight On the Settling Responses
Authors: Kennedy J. S. , Booth C. O. 
Published: April 2021

ABSTRACT
Previous evidence that fresh-winged adult aphids become increasingly ready to settle down on a leaf the longer they have flown beforehand, and that this effect is appreciable after less than 1 min. flight, was confirmed with aphids allowed to fly and alight freely without interference. The settling responses initiated after flight were quickly inhibited again by an unsuitable leaf, with reversion to flight, but repeated flights had a cumulative effect. The excitability of the settling responses increased as an after-effect of flights in which the excitability of flight itself (measured by the rate of climb) was not falling and was even increasing. It is concluded that settling is not released by flight but is positively ‘primed’ while it is inhibited by flight, these two activities having been shown to be centrally antagonistic. Settling may be further promoted by some peripheral physiological feedback during long flights when the rate of climb falls, but this is a secondary, merely reinforcing effect. The primary effect is given the name ‘antagonistic induction’. It resembles successive induction or rebound in lower reflex action As a principle of nervous integration at the behavioural level it calls in question previous assumptions concerning internal drives in aphids and other animals. Host plant selection occurred as a result of the sequence of settling responses being broken off at an earlier stage on one kind or age of leaf than another. Most commonly the difference of behaviour appeared only after a first probe, but following very short flights discrimination was sometimes observed without any probing.
Osmoregulation in Ligia Oceanica and Idotea Granulosa
Authors: Todd Mary E. 
Published: April 2021

ABSTRACT
The osmoregulatory response of Ligia oceanica and Idotea granulosa to the range of the experimental variables was similar. They were both hyperosmotic relative to the medium and the difference between internal and external concentration increased as the salinity of the medium decreased. In 100 % sea water the osmotic concentration of the blood of Ligia oceanica was markedly above that of the medium, whereas in Idotea granulosa the blood was only marginally hyperosmotic. In Ligia oceanica the blood concentration changed little in 100 and 75 % sea water, but dropped significantly between 75 and 50% sea water, whereas blood concentration in Idotea granulosa dropped significantly throughout the test range of salinities. The more efficient osmoregulation of Ligia oceanica in 25 % sea water is reflected in the mean freezing-point depression of the blood Δi = 1 · 65, compared with Δi = 0 · 90 in Idotea granulosa. In both species the osmotic concentration of the blood was influenced by season, by temperature and by a temperature-salinity interaction. Neither size nor sex of the animal influenced osmotic concentration of the blood.
Delayed Responses in Octopus
Authors: Dilly P. N. 
Published: April 2021

ABSTRACT
Octopuses were tested for their ability to perform delayed responses after varying delays and brain lesions. Octopuses delayed for 10 sec. were capable of accurate performance without training. In order to make a correct response after 20 or 30 sec. delays some ‘learning’ is needed. Animals without vertical lobes or without median superior frontal lobes delayed for 30 sec. responded correctly. The majority of correct attacks were ‘swimming attacks’ in which the animal swam through the water without contacting the walls of the tank. ‘Shaking up’ the animals and disturbing them so that any orientating contact between the octopus and the door and sides of the tank was destroyed, did not decrease the accuracy of the response. The time taken for the response in these experiments was slightly increased.
Comparative Physiology of the Vertebrate Autonomic Nervous System
Authors: Burnstock G. , Campbell G. 
Published: April 2021

ABSTRACT
A histological study of the structure of the urinary bladder of the ringtail possum has been made. The innervation of the bladder has been studied in vitro, using the technique of analytical pharmacology. The bladder has well-defined inner longitudinal and outer circular muscle layers. Nerves supplying the bladder are found both in the pelvic nerves and in the vesical nerves which run with the vascular supply of the bladder fundus. Ganglia have been demonstrated along the trunks of the vesical nerves and also aggregated at the bladder neck. The response of the bladder to stimulation of either nerve supply in situ or in vitro is always a simultaneous contraction of both longitudinal and circular muscles. Inhibitory responses to nerve stimulation have never been observed. The optimal frequency for stimulation of these nerves at 30° C. is 50 pulses/sec. The bladder is contracted by ACh and 5-hydroxytryptamine, but is relaxed by adrenaline, noradrenaline and histamine. The response to nerve stimulation is reduced by atropine and potentiated by eserine. Adrenergic blocking agents do not affect the nerve-mediated response unless they also affect the response to applied ACh in a similar manner. Ganglionic blocking agents, in concentrations which do not reduce the response to ACh, cause up to a 40% reduction of the response to stimulation of either the vesical or the pelvic nerves. It is concluded that the nerve fibres supplying the possum bladder are cholinergic, perhaps 40 % of them being stimulated pre-ganglionically. The evolutionary significance of these observations is discussed. Some points of pharmacological interest have been discussed in relation to drug actions on placental mammal preparations.
Studies On the Mode of Action of the Diapause Hormone in the Silkworm, Bombyx Mori L
Authors: Hasegawa Kinsaku 
Published: April 2021

ABSTRACT
The action of the diapause hormone has been studied by injecting extracts of the heads of male moths or of the brain-suboesophageal ganglion complexes of pupae into pupae expected to produce non-diapause eggs. The effect of the injection of hormone upon young oocytes is to make them develop into diapause eggs. Older oocytes, which have already acquired non-diapause characters, are not affected. The hormone is almost completely inactivated when injected on the day of pupation. The hormone is most effective when injected into pupae 2-3 days old, at which stage the ovarioles have started to grow vigorously. It is ineffective 1-2 days before adult emergence, by which time all the oocytes have acquired non-diapause characters. The hormone is inactivated in all pupae irrespective of whether they are destined to produce diapause eggs or non-diapause eggs. Inactivation of diapause hormone (in contrast to that of juvenile hormone) is partially relieved by exposure to low temperature or by simultaneous injection of indian ink. The extracts prepared as in (1) above do not serve as a stimulant for the brain causing the suboesophageal ganglion to produce diapause hormone. The action of the extract faithfully reflects the function of the diapause hormone which originates in the suboesophageal ganglion.
Oxygen Requirements and the Physiological Suppression of Supernumerary Insect Parasitoids
Authors: Fisher Roderick C. 
Published: April 2021

ABSTRACT
The oxygen content of the haemolymph of mature larvae of Ephestia kühniella has been measured in healthy individuals and in those parasitized by the ichneumonid Nemeritis canescens. In the latter the oxygen content decreases with the progress of parasitism. The respiratory rate of first, second- and third-instar larvae of Nemeritis has been measured and found to increase rapidly at the end of the first instar, at about the time at which the phenomenon of physiological suppression appears. The partial pressure of oxygen in the gas mixture surrounding the Ephestia larva affects the oxygen content of its haemolymph proportionally and so was used to alter the availability of oxygen to the parasite in vivo. The survival of Nemeritis larvae increases with the availability of oxygen in the haemolymph of its host. The capacity for survival under conditions of low oxygen tension is minimal for eggs and newly hatched larvae of Nemeritis, but rapidly increases with age. The hypothesis of physiological suppression of supernumerary parasitoid larvae by asphyxiation is discussed with respect to these observations and is held to be supported by them.
Water Balance in the Aquatic Bugs Notonecta Glauca L. and Notonecta Marmorea Fabr. (Hemiptera; Heteroptera)
Authors: Staddon B. W. 
Published: April 2021

ABSTRACT
A study has been made of water balance in two closely related species of aquatic bug, Notonecta glauca L. and N. marmorea Fabr., and the mechanism appears to be the same in both. Ammonia is a major nitrogenous excretory compound and the bulk of the ionic material in the rectal fluid is in the form of ammonium bicarbonate. Water is eliminated through the excretory system and the output of water appears to be related to the output of ammonia. The relationship is such that the concentration of ammonia in the rectal fluid tends to a limiting value of about 120 mm./l. Water is gained by uptake through the cuticle and gut. The volume of water ingested is closely related to the volume of water eliminated through the excretory system and the uptake of water through the cuticle appears to be constant at about 7 % of the body weight per day. At the time of moulting the increase in weight is in part due to retention of water in the tissues and in part due to the retention of water in the rectum. It is pointed out that the mechanism by which water balance is maintained in Notonecta may not be of wide application to other aquatic insects.
Studies On the Respiration of Sea-Urchin Spermatozoa
Authors: Mohri H. , Yasumasu I. 
Published: April 2021

ABSTRACT
The effect of PCO2 on the respiration and motility of sea-urchin spermatozoa was studied on Anthoddaris crassispina. Some points were also corroborated on Hemicentrotus pulcherrimus, Pseudocentrotus depressus, Paracentrotus lividus and Sphaerechinus granularis. It was found that any level of CO2 above 1 %, both in oxygen and in air, inhibited the O2 uptake of spermatozoa suspended in sea water, measured polarographically with a vibrating platinum electrode. The inhibitory effect paralleled the PCO2and was completely reversed by introducing oxygen or air. pH variations between 8·50 and 6·75 had no influence on O2 uptake, when the pH was stabilized with 0·05 Mhistidine-HCl-NaOH. O2 uptake was, however, reduced to some extent outside this range, especially on the acid side. Although the increase in PCO2 is inevitably followed by a decrease in pH, the inhibitory effect of CO2 far exceeds that caused by the reduction in pH. The O2 uptake rate was little affected by the addition of both bicarbonate and carbonate ions to the suspending medium, although the former had a slightly stimulating effect at certain concentrations. In buffered sea water, CO2 had little influence on O2 uptake even at partial pressures as high as 10% which inhibited the bulk of O2 uptake in sea water. Sperm motility was also inhibited by CO2. In this case, too, the inhibition paralleled the PCO2 and was completely reversible. The effect was more pronounced in air than in oxygen, and in dense sperm suspensions than in dilute ones. These results suggest that gaseous CO2 is the factor responsible for the inhibitory effect. The possible role of CO2 in the dilution phenomena of sea-urchin spermatozoa is discussed.
Studies on the Myoneural Physiology of Echinodermata
Authors: Boltt R. E. , Ewer D. W. 
Published: April 2021

ABSTRACTThe responses to drugs of a preparation of the lantern retractor muscle of Parechinus are described. The muscle responds with a contracture to acetylcholine, but atropine is without action. Nicotine and eserine enhance the tone of a preparation, the latter also causing rapid rhythmic activity. Curare, in low concentration, enhances tone and activity but is inhibitory at higher dosages. Adrenaline inhibits activity and abolishes tone. The action of acetylcholine is antagonized by both adrenaline and curare. It is suggested that the results observed with curare and eserine are independent of their effects upon cholinergic transmission and that their seat is at the level of the motor complex of the muscle.
In VitroCulture of Embryos in the Silkworm,Bombyx MoriL
Authors: Takami Takeo 
Published: April 2021

ABSTRACTSilkworm embryos decapitated before the differentiation of neuroblasts, or before differentiation of the prothoracic glands, were cultured in vitro. Brainless embryos which developed from these decapitated explants detached the cuticle, suggesting that the’moult’ of cultured embryos does not require any hormonal action of the brain in the silkworm at least for its initiation. The prothoracic gland was not found to be necessary even for occurrence of the embryonic moult. The author’s results obtained by embryo culture in the silkworm are contrary to those obtained by ligaturing experiments in the locusts. This difference between the two cases present important questions about the nature of the moult in cultured silkworm embryos, which must be answered by further investigations.
Length of Life of the Sexes inNasonia Vitripennis(Walker) (Hymenoptera, Pteromalidae) Under Conditions of Starvation
Authors: King P. E. , Hopkins C. R. 
Published: April 2021

ABSTRACTAt relative humidities of 65 and 100% the mean length of life of virgin or mated females of Nasonia vitripennis is greater than that of the males under similar conditions. The sexes showed no significant difference in their respiratory rates, as measured by Warburg manometer or Macfadyen’s continuous recording respirometer. An examination of the organs of fed and starved individuals of both sexes showed that the only major change in the organs of starved individuals which can have any bearing on the length of life is the marked reduction in length of the ovaries resulting from resorption of the mature eggs. It is suggested that the resorbed eggs supply the female with the nutriment which enables it to outlive the male when both are starved.
Control of Luminescence in Hemichordates and Some Properties of A Nerve Net System
Authors: Baxter Charles H. , Pickens Peter E. 
Published: April 2021

ABSTRACT
Luminescence in Ptychodera and Balanoglossus is normally neurally mediated. The main luminescence appears to be intracellular; in addition a luminous slime is secreted. The response of individual photocytes is all-or-none, but requires neuroeffector facilitation which grades intensity by recruitment (in contrast to crustacean muscle). Repetitive discharge, both to mechanical and single electrical stimuli, is considered to be a prime factor together with interneural and neuro-effector facilitation, in determining spread of excitation in the general plexus. Four types of spread of luminescence occur, differing in conduction velocity polarization of spread, area of spread, necessary conditions for elicitation and adequate stimulus. At least three different neural pathways are involved. Prolonged autoexcitatory displays produce luminous waves arising repetitively from the same locus and from multiple loci; the general plexus is implicated. There is a diurnal rhythm of responsiveness to stimuli. This is attributed to the photocyte rather than to the nervous system.
Frog Fast Muscle: II. A Method of Measuring Internal Series Compliance
Authors: Pennycuick C. J. 
Published: April 2021

ABSTRACT
Methods which have been used in the past for estimating internal series compliance are discussed. A new method is described in which measurements of (a) rate of change of tension, and (b) speed of shortening are made in the isometric and isotonic phases respectively of a contraction containing a transition from one type of contraction to the other. If the mechanical power output of the muscle is assumed the same just before and just after the transition, the total series compliance can be obtained. The method is found to agree with Wilkie’s quick-release method, provided parallel elastic structures are not carrying significant tension at the transition.
The Location of the Photoperiodic Receptors in the Aphid Megoura Viciae Buckton
Authors: Lees A. D. 
Published: April 2021

ABSTRACT
Although the photoperiodic reactions of insects and mites have been studied quite extensively (Lees, 1955 ; de Wilde, 1962), the site of the photoreceptors is still unknown. The light pathway does not seem to involve the eyes. Thus Tanaka (1950) observed that the photoperiodic control of diapause in the silkworm Antheraea pernyi was not affected by cauterizing the lateral ocelli of the 4th-instar larva—a treatment that resulted in the complete disappearance of these organs in the following instar. De Wilde, Duintjer’ Mook (1959) have shown that adult Colorado beetles (Leptinotarsa decemlineata) respond normally to day-length after the compound eyes have been covered with black paint or destroyed with a cautery.
Less progress has been made in identifying the regions of light sensitivity. Geispits (1957) was able to fit an opaque hood over the head of a Dendrolimus larva which was otherwise continuously illuminated. With this covering in place for 12 hr. daily all the insects subsequently entered diapause. But none did so when only the body was shielded from light, showing that the photoreceptors were located on the head. Since the wavelength sensitivity of the visual and photoperiodic response showed some correspondence Geispits was led to the further conclusion that the eyes were in fact the photoperiodic receptors. But in view of the preceding evidence this conclusion seems questionable.
The Locomotion of Nematodes
Authors: Gray J. , Lissmann H. W. 
Published: April 2021

ABSTRACT
The form and frequency of the waves passing down the bodies of small free-living nematodes (Panagrellus, Rhabditis and Turbatrix) depend on the nature of the external medium. Observations of animals moving in such media as syrup, agar gels, and dense suspensions of particles suggest that the relationship between the speed of progression of the animal to the speed of propagation of the waves along the body, depends on the relative resistance exerted by the medium to displacement of the body in directions normal to and tangential to its own surface. When swimming in water the body of a nematode yaws periodically in a transverse plane and the axis of progression does not coincide with that of the waves; the displacement of an element of the body relative to the medium depends on its position on the body. The envelope of one complete wave exhibits two characteristic nodes. A suspended particle originally situated near the anterior end of a swimming animal moves tangentially backwards along the surface of the body, but the speed at which it does so is not constant and is always much less than that at which the waves travel relative to the ground. The average speed of a particle close to the surface of the body is about one quarter of that of the waves. When plotted relative to the ground the path of displacement of a particle exhibits characteristic loops. When viewed from above and in the direction of the animal’s progression, all particles on the left side of the body traverse their loops in a clockwise direction ; all those on the right side move anticlockwise. There is a highly characteristic pattern of circulation round the body of the animal. Water in the vicinity of a wave crest moves in the opposite direction to that of the propagation of the waves, but in the same direction as the waves when situated in a wave trough. The circulation extends for a considerable distance from the surface of the body. The flow round the body of a swimming nematode is essentially the same as that in the neighbourhood of an undulating sheet of rubber. Its analysis presents an interesting but difficult hydrodynamical problem.