bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proprioceptive Leg Reflexes in Cockroaches
Authors: Wilson Donald M. 
Published: April 2021

ABSTRACT
Proprioceptive feedback from the moving wings of locusts contains information which could be sufficient for the control of the timing of the wing-muscle contractions. It has been found, however, that at the high frequency of limb movement used in flight this phasic information content is lost in the ganglionic transfer (Wilson & Gettrup, 1963). During rapid running the legs of cockroaches also oscillate at high frequencies, sometimes as rapidly as wing movements of similar-sized animals. It is therefore necessary to know whether the frequency response capabilities of the leg reflexes are similar to or different from those of the wings in order to understand how the legs are coordinated. If the leg reflexes are limited to the same range as that available to the wing reflexes, then coordination of the legs would necessarily depend upon ganglionic phasing mechanisms ; that is, the elementary pattern of leg movements could be due to central nervous control alone, as is true of the locust wing control (Wilson, 1961). However, it can be shown that the phasic leg reflexes are capable of operation at frequencies even greater than those encountered in running. Apparently the significant limitation on rate of leg movement is not nervous but mechanical; that is, due to the maximum rate of contraction of the muscles.
Measurements of the Oxygen Tension in the Lumen of the Small Intestine of the Domestic Duck
Authors: Crompton D. W. T. , Shrimpton D. H. , Silver I. A. 
Published: April 2021

ABSTRACT
By use of an oxygen electrode measurements of oxygen tension have been made in the lumen of the small intestine of the domestic duck in the region occupied by the acanthocephalan parasite, Polymorphus minutus. The tension was found to vary from 25 mm. Hg close to the villi to less than 0·5 mm. Hg in the centre of the lumen.
Co-Ordination of Successive Activities in an Aphid. Reciprocal Effects of Settling on Flight
Authors: Kennedy J. S. 
Published: April 2021

ABSTRACT
Individual aphids were allowed to fly for set periods, to land on a host leaf, a non-host leaf or a card and make settling responses to it, and then to take off again, without handling, in a laboratory flight-chamber with continuous recording of the rate of climb as a measure of flight activity. The after-effect of a landing was typically a boosting or rebound of flight, which was sometimes accompanied within seconds by depression of it. The boosting effect of landings summated, and the depressing effect waned, through a series of 1 min. flights. Both effects were greater after landings on a leaf than after landings on a card, where the settling responses were weak and flight was therefore inhibited only briefly. Normally the depressing after-effect was greatest with landings on the host leaf, where the settling responses were strongest and flight was inhibited the longest. When flight had been brought up to a highly excited state by previous landings, a landing on the host had little or no depressing after-effect upon flight and now boosted it more than landings on a non-host leaf or card. The strength of the flying aphids’ phototactic response in the horizontal (yawing) plane varied with the strength of their photokinetic response measured as the rate of climb. The results effectively precluded the possibility of flight rebound being due to the rest gained while settled ; they support the conclusion that both the rebound and the depression of flight following a landing are after-effects of the temporary inhibition of flight by the settling responses. These two after-effects of settling on flight duplicate the reciprocal after-effects of flight on settling described previously as antagonistic induction and antagonistic depression. Both appear to depend on central nervous interaction rather than peripheral feedback.
Sensory Regulation of Wing Twisting in Locusts
Authors: Gettrup Erik 
Published: April 2021

ABSTRACT
The campaniform sensilla of the wings are necessary for the regulation of wing twisting in locusts. Control of forewing twisting during periods of constant lift depends upon the hind-wing sensilla being intact, whereas the forewing sensilla are essential for stability about the three body axes. The campaniform sensilla are located on the ventral surface of the wings. Two groups are present on the subcosta of the forewing and one on the subcosta of the hindwing. A few single sensilla occur on the costa. The cuticular parts of sensilla from distal and proximal forewing groups differ with respect to the lengths of their ovally shaped cuticular parts. The sensilla are orientated with the cupolas parallel to the long axis of the wing, except for those of the proximal forewing group, which are arranged in a fan. During steady-state flights activity from campaniform units was high during the downstroke and low during the first part of the upstroke. Significant changes in the response were found to occur when the body angle was changed. The effect of a 15° change in body angle on the motor output to the basalar and subalar muscles is described. At the start of a flight these motor patterns are rather unstable, units falling in and out. Stability is gained within 10 sec. A distinct part of the response from the campaniform units in the hindwings can be abolished by the application of an anodic block. The duration of the blocking pulse equalled one-sixth of the flight period. The effect on regulation of forewing twisting varied according to the part of the response which is removed. Regulation could be abolished almost completely when the anodic block was introduced during the first part of the hindwing downstroke. When the anodic block is removed, twist regulation builds up again and is completed within 100-150 wing-beats. Free flights including both intact and deafferentated animals made possible an evaluation of the importance of the different groups in stability reactions. It was shown that control of angular movement is accomplished by the forewing groups only, especially the proximal ones. The integrative processes within the pterothoracic ganglia are discussed. During the constant-lift reaction, the slow, intersegmental reflex for control of forewing twisting seems to depend on central processing and memorizing of measurements of total lift. The sensory input from the hindwings is phasic and patterned, but it is still undecided whether it is the phase or the pattern which is the essential parameter.
Rubber-Like Properties of the Inner Hinge-Ligament of Pectinidae
Authors: Alexander R. McN. 
Published: April 2021

ABSTRACT
The inner hinge-ligament of Pectinidae (Lamellibranchiata) is an elastic block of amorphous cross-linked protein, plasticized with water. It acts as a compression spring, and is the antagonist of the shell adductor muscle. Its elasticity is shown to be rubber-like, in that the elastic restoring force is mainly due to entropy changes. Rubber-like elasticity has been demonstrated by other authors in two other proteins (elastin and resilin). Pectinidae swim by rapid opening and closing of the shell. The resilience of the inner hinge-ligament of Chlamys at the frequency of the swimming movements is at least 91%. The inner hinge-ligament of Pectinidae is compared with other proteins which show long-range elasticity.
Aspects of the Neurophysiology of Buccinum Undatum L. (Gastropoda)
Authors: Bailey D. F. , Laverack M. S. 
Published: April 2021

ABSTRACT
Recordings have been made from various central neurones of Buccinum undatum, the common whelk, particularly in response to peripheral stimulation of the osphradium. These central responses show that the osphradium is sensitive to the application of a restricted range of chemical stimuli, but insensitive to mechanical stimulation with suspended particulate matter. The most pronounced central activity was seen in response to the addition of a sea-water extract of Mytilus edulis. This animal is one normally preyed upon by Buccinum. The synthetic chemicals most closely mimicking this effect were glutamic and aspartic acids, which were effective at low-threshold concentrations. Other chemicals of 4-6 carbon-atom chains with terminal carboxyl groups were effective stimuli and it therefore appears that the dicarboxylic nature of the effective amino acids plays a major part in the stimulatory process. Intracellular recordings indicate that the peripheral input from osphradial chemoreceptors and mantle mechanoreceptors may be either excitatory, inhibitory or without effect on central neurones.
This work was carried out whilst one of the authors (D.F.B.) held a D.S.I.R. Studentship. Part of the equipment was obtained on a Royal Society Grant-in-Aid to M.S.L.
A Lepidopteran Saline: Effects of Inorganic Cation Concentrations On Sensory, Reflex and Motor Responses in A Herbivorous Insect
Authors: Weevers R. De G. 
Published: April 2021

ABSTRACT
The inorganic cations in the haemolymph of Antheræa pernyi larvae and pupae were analysed by flame photometry. Synthetic media based on these analyses were compared with haemolymph in their effects on the muscle action potential and on the response of the dorsal muscle receptors to a standard stretch. The best match with haemolymph was obtained in all cases with concentrations of divalent cations considerably below the values found by flame photometric analysis. Binding to haemolymph proteins is probably not the major factor responsible for lowering the ionic activities of calcium and magnesium. The role of magnesium in neuromuscular transmission is discussed. It is concluded that in phytophagous Lepidoptera this ion may carry a proportion of the muscle action current.
I am grateful to my supervisor, Prof. G. M. Hughes, for guidance and encouragement during this work, and to the D.S.I.R. for financial support in the form of a research studentship.
The Physiology of A Lepidopteran Muscle Receptor
Authors: Weevers R. De G. 
Published: April 2021

ABSTRACT
The afferent discharge from the lepidopteran MRO provides complex information to the c.N.s. on the parameters of movements occurring at the periphery. Not only ‘position’ but also ‘movement’ and ‘acceleration’ components are present in the response. While the position response is very nearly linearly related to the length of the receptor, the movement response is related to the square root of the rate of stretch. The acceleration response bears a more more complex relation to the stimulus. The responses of the sense organ to stretching are discussed in relation to the possibility of using methods of linear systems analysis. The observed non-linearities preclude such treatment of the present data.
I am very grateful to my supervisor, Prof. G. M. Hughes, for guidance and encouragement during this work, and to the D.S.I.R. for financial support in the form of a research studentship. I am also indebted to Dr R. H. J. Brown for the basic design of the stretcher.
The Permeability to Water of the Cuticles of Some Adult Water Bugs
Authors: Staddon B. W. 
Published: April 2021

ABSTRACT
The permeability to water of the cuticles of some adult water bugs has been measured using deuterium oxide (heavy water) as tracer. The D2O permeability constant of Ilyocoris cimicoides cuticle was 1-7 × 10-2 cm./hr. at 18° C. There was no apparent difference between the rates of D2O influx and efflux at 18° C., but at 28° C. a possible difference between them was indicated. The Q10 of the influx was 1·8 over the temperature interval 8-18° C., 1·5 over the interval 18-28° C. The estimated osmotic water uptake was 2·3% of the body weight per day at 18° C. In Corixa dentipes adults the D2O permeability constant of the cuticle was 2·3 × 10-2 cm./hr. at 18° C. and the derived osmotic water uptake 3% of the body weight per day. In Notonecta glauca adults the corresponding values were 1·4 × 10-2 cm./hr. and 1·8% of the body weight per day.
Oxygen Transport by the Circulatory System of the Green Iguana (Iguana Iguana) at Different Body Temperatures
Authors: Tucker Vance A. 
Published: April 2021

ABSTRACT
Oxygen consumption, stroke volume, heart rate and the difference in oxygen contents of arterial and venous blood (AV difference) were measured in the resting iguana at body temperatures of 20, 30 and 38° C. Oxygen consumption increased by a factor of 4·4 as temperature changed from 20 to 38° C. This increase was accomplished by a decrease in stroke volume by a factor of 0·5, and increases in heart rate and A V difference by factors of 4-1 and 2-2, respectively. During activity increases in oxygen consumption at a given temperature were accompanied by increases in heart rate and A V difference, but stroke volume did not change consistently. The percentage saturation of arterial blood with oxygen in the iguana may differ in the right and left systemic arches. In some lizards, both arches carried equally saturated blood, but in others the left arch carried blood containing less oxygen than the right arch. An hypothesis is presented concerning the function of the double systemic arches and incompletely divided ventricles of lizards. These structures may be a device for permitting increased cardiac output associated with thermoregulation to bypass the lungs while maintaining a supply of well-oxygenated blood to the head. Data on oxygen capacity, percentage saturation of blood with oxygen, haematocrit and pH of iguana blood are included in this study. This study was supported by a National Science Foundation Postdoctoral Fellowship. I am indebted to Prof. W. R. Dawson, who provided laboratory facilities and advice to make this study possible.
The Hormonal Control of Colleterial Gland Secretion
Authors: Willis J. H. , Brunet P. C. J. 
Published: April 2021

ABSTRACT
Methods for the quantitative assay of the activities of the left and right colleterial glands of adult cockroaches (Periplaneta americana’) are reported. The former involves the spectrophotometric measurement of the content of protocatechuic acid glucoside of the gland ; the latter the measurement of glucosidase activity by orthodox use of a chromogenic substrate. Glucoside and glucosidase have been studied in terms of accumulation and turnover. The accumulation of the glucoside requires the presence of active corpora allata, but glucosidase synthesis is seemingly independent of this.
The Excretory Role of Pteridines in Insects
Authors: Harmsen R. 
Published: April 2021

ABSTRACT
Previous work on the storage excretion theory of pteridines is summarized briefly, and the controversial aspects of this theory are discussed. A general model for all nitrogen-containing substances in an animal body is presented. The possible pathways for pteridines in this model are discussed, and the storage excretion hypothesis is related to the model. Storage and excretion of nitrogen-containing substances in Pieris brassicae were compared chromatographically on a quantitative basis. Only traces of the pteridines are excreted, the majority being stored, mostly in the adult cuticular scales. Only 20% of the uric acid is excreted; the xanthine is quantitatively stored in the fatbody. Removal of part of the wing storage potential increases excretion and fatbody storage only very slightly. There is a reduction in overall pteridine synthesis. A partly scaleless mutant, cerula, of P. brassicae also shows a slight increase in pteridine excretion coupled with an overall decrease in pteridine synthesis. Vanessa io, a related species not containing large quantities of pteridines, was closely compared with P. brassicae. In Vanessa nearly half the pupal pteridines are excreted with the meconium, and no storage is found in the cuticular scales. Several insects of other orders were investigated quantitatively. Only in some Hemiptera were pteridines found, stored in quantities comparable to those in Pieridae. Using an ultra-micro Kjeldahl technique for total soluble nitrogen, the relative role of purines, pteridines, and some other minor substances, both in storage and excretion, was established. It is obvious that in Pieridae the pteridines account for a much higher percentage of the total highly oxidized nitrogen produced (14%) than they account for in most other insects. The Pieridae differ further in storing most of these pteridines irreversibly in the cuticular scales of the adult. The evidence strongly suggests that the Pieridae have evolved a metabolic mechanism of which pteridines are the general end-product as well as a mechanism of dry storage excretion for these end-products. The pigmentation effect of cuticular pteridine deposition is considered a sideeffect.
Activity in the Optic Nerve of Pecten Maximus in Response to Changes in Light Intensity, and To Pattern and Movement in the Optical Environment
Authors: Land M. F. 
Published: April 2021

ABSTRACT
In the eye of Pecten maximus there are two functionally independent retinae. The proximal retina contains receptors which respond to increase of illumination, those of the distal retina respond to decrease. The activity of each retina was investigated by recording from the optic nerve, which contains the axons of both types of receptor. Visual stimuli used included changes in overall illumination, pattern and movement. Dark adaptation was also studied. The ‘off’ response is generated by cells which are anatomically primary receptors. Two light dependent processes are involved: a slow development of excitability and a simultaneous inhibition of action potentials. The reflected image is important in movement perception. Only the distal cells lie in the image plane, and they can respond to moving objects, as these cause dimming of successive cells when their images cross the retina. Dark objects subtending 2° or more at the eye, and moving through more than 2°, are effective stimuli. Light objects are also effective, provided they have remained stationary for several seconds before moving. There is no response to stationary pattern. The proximal cells respond only to increase in overall light intensity. These findings are discussed in relation to the behaviour of Pecten.
Neuromuscular Transmission in A Sea Anemone
Authors: Josephson Robert K. 
Published: April 2021

ABSTRACT
Brief electrical potentials can be recorded from a suction electrode over the marginal sphincter or over a tentacle of the anemone Calliactis polypus following appropriate stimulation of the anemone. These potentials are thought to be muscle action potentials because they precede contraction by about 12 msec. (29−31° C.) and their size is smoothly graded with the size of the contraction. The tentacles and sphincter are activated by a through-conducting system in the oral disk and column. As with other anemones studied, two stimuli are required to evoke sphincter contraction. The maximum interval between an effective pair of stimuli is about 600 msec, and the sphincter potential and contraction increase with decreasing intervals to a minimum interval (as short as 15 msec.) below which there is no response to the second shock. Tentacles behave similarly except that they often produce small potentials and sometimes tiny contractions to single stimuli. During repetitive stimulation the muscle potentials facilitate and the individual contractions both facilitate and sum. The tentacle musculature becomes maximally active earlier in a stimulus burst than does the sphincter.
Sound Production and Reception In A Cockroach
Authors: Guthrie D. M. 
Published: April 2021

ABSTRACT
The cockroach Henschoutedenia epilamproides produces distinctive patterns of sound, on being disturbed, by means of a stridulatory apparatus. The carrier frequency of the sound is between 4·5 and 5·0 kcyc./sec., and is amplitude-modulated to form pulses. These pulses are grouped to form chirps, which are emitted singly or in a series. The structure of the longer chirps (50−100 msec.) may be quite complex. While the circumstances under which sound is usually produced in the laboratory suggests that it is not important in intraspecific communication, it may be of some importance to the cockroach to hear its own sound. Recordings made from the cereal nerve show that the cockroach responds hardly at all to its own sound, and very poorly to artificial tones above 400 eye./sec. The cereal afferents are most sensitive to tones of 50 eye./sec., and will respond to less than 60 db. at this frequency. Although the auditory performance of Henschoutedenia cereal receptors appears poor by comparison with Periplaneta americana, their responses to air movements are most striking. Some difficulty was experienced in standardizing this form of stimulation, but it appeared that Henschoutedenia was much more sensitive than Periplaneta to this form of stimulation. Experiments with rodents (Rattus rattus and Clethrionomys glareolus) lent some support to the idea that the cockroach sound mimicked the cries of rodent predators, and had some deterrent effect on them.
Neuromuscular Mechanisms of Burrow Irrigation in the Echiuroid Worm Urechis Caupo Fisher & Macginitie
Authors: Lawry James V. 
Published: April 2021

ABSTRACT
The anatomy of the muscular and nervous systems of Urechis is described. An apparatus is described whereby it is possible to record the parameters of the peristaltic waves used in irrigating the tube. Urechis is continuously active and shows no periodicity under conditions of constant temperature. About 1280 peristaltic waves are initiated, and about 29 L of water are moved, in 24 hr.
The fluid dynamics of the bivalve molluscs, Mya and Margaritifera
Authors: Trueman E. R. 
Published: April 2021

ABSTRACT
A comparison is made of the fluid dynamics of a shallow, yet actively, burrowing bivalve, Margaritifera, with the sessile, deeply buried Mya armaria. In both adduction produces high pressures (up to 100 cm.) in the mantle and the pericardial cavities which are utilized in Margaritifera for locomotory purposes, in Mya principally for siphonal extension. With siphonal and pedal apertures closed the mantle cavity of Mya is virtually watertight and acts, together with the blood, as the fluid of an antagonistic muscle system, whereby adduction causes siphonal extension and siphonal retraction pro­duces an increase in gape of the valves. The close interaction between these two muscle systems is illustrated by pressure recordings of Mya in the normal buried position. Siphonal movements are shown to be associated with divarication of the valves and accompanying pressure changes. Consideration is given to the haemodynamics of Mya and by contrast with the high pressures involved in locomotion or siphonal movement, maximum pressures of only 2-5 cm. were recorded from the heart, producing a sluggish circulation. The higher pressures derived from the body musculature make an important contribution to movements of the blood.