bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relationship between Nutrition, Hormones and Reproduction in the Blowfly Calliphora Erythrocephala (Meig.)
Authors: Strangways-Dixon J. 
Published: April 2021

ABSTRACT
When female blowflies are fed unlimited quantities of ‘protein’ (marmite and milk) and sugar solutions, their corpora allata (c.a.) volumes increase before and decrease during yolk formation in normal females but hypertrophy in ovariectomized flies. If fed sugar solution alone, the ovaries of the flies do not mature and the c.a. in both normal and ovariectomized females remain small. The interpretation and control of these variations in volume were investigated. When ovariectomized or normal females are fed ‘protein’, their c.a. volumes increase in proportion to the quantity consumed. When ‘protein’ is removed from the diet, the c.a. decrease in size. The c.a. respond similarly in both types of fly up to the stage at which yolk is normally deposited. If a further quantity of ‘protein’ is ingested at this stage, the c.a. of normal females increase slightly in volume and then decrease during yolk deposition. But the c.a. of ovariectomized females hypertrophy before decreasing in size. The decrease in c.a. volume during yolk formation may be virtually eliminated by forcing the flies to ingest excess quantities of ‘protein ‘during this phase. The graded response of the c.a. to ‘protein’ consumption suggests that fluctuations of c.a. volume represent variations in activity induced (proportionately) by ‘protein’ metabolites in the blood (there is no accumulation of ‘protein’ in the gut). The decrease in size during yolk formation is due to the removal of ‘protein’ metabolites by the ovaries for the purpose of yolk formation. In ovariectomized flies, these yolk precursors accumulate in the blood causing the c.a. to become hyper-active as indicated by hypertrophy. The responses of the c.a. to ‘protein’ consumption do not appear to be unduly affected by denervation, cutting of the nervi oesophagi or of the cardiac-recurrent nerve. There is slight evidence that the corpus cardiacum is able to store c.a. hormone.
An Isolated Insect Ganglion-Nerve-Muscle Preparation*
Authors: Hoyle Graham 
Published: April 2021

ABSTRACT
A preparation is described which consists of an isolated locust metathoracic ganglion, together with one motor nerve and the skeletal muscle which it supplies (the anterior coxal adductor) in a state suitable for tension recording. Mechanical responses were recorded from the whole muscle, or bundles of fibres and electrical responses of single fibres were recorded intracellularly. Some fibres were found in the muscle which have unusual properties. A single excitatory axon supplies the muscle. Preganglionic stimulation applied to cut nerve trunks may excite an inhibitory-conditioning axon supplying the same muscle. Direct stimulation of the motor nerve was combined with preganglionic stimulation in order to excite the two axons, and their interaction in relation to contraction of the muscle was studied. The preparation shows spontaneous activity in the single excitatory axon supplying the muscle. Various preganglionic stimulations were found to cause prolonged changes in the spontaneous motor output. By correlating the stimuli to the output in certain ways, long-lasting changes in mean output frequency were obtained. These may be regarded as a simple form of learning.
Functioning of the Inhibitory Conditioning Axon Innervating Insect Muscles*
Authors: Hoyle Graham 
Published: April 2021

ABSTRACT
The jumping muscle of locusts is supplied by three motor axons (Hoyle, 1955 a), one of which gives rise to large twitch contractions when stimulated with a single shock and is termed the fast (F) axon, whilst another gives rise to slow contractions only, when repetitively stimulated, and is termed the slow (S) axon (Hoyle, 1955 b). The third axon was found not to give a contraction when stimulated alone but it did cause a hyperpolarization in some of the muscle fibres Thus, by comparison with peripheral inhibitory action at crustacean neuromusclar junctions (Fatt & Katz, 1953), amphibian heart (Hutter & Trautwein, 1956) and cat spinal cord (Eccles, 1953), its function could be expected to be inhibitory; but Hoyle (1955b) found that stimulation of this axon at the same time as stimulation of either of the two excitatory ones did not lead to mechanical inhibition. Instead, the mechanical responses were enhanced, though the effect was slight so functional significance could not be ascribed to it with confidence. Since this phenomenon could not be fully understood it has remained in the background awaiting further investigation.
The Hormonal Control of the Development of Hairs and Bristles in the Milkweed Bug, Oncopeltus Fasciatus, Dall
Authors: Lawrence Peter A. 
Published: April 2021

ABSTRACT
As in Rhodnius, the larval Oncopeltus has bristles which are supplemented at each moult. However, at metamorphosis a dense population of non-innervated hairs develops. Implantation of corpora allata into 5th-stage larvae showed that the development of these hairs can be inhibited universally or locally by the juvenile hormone (JH). Transplantations of integument between 5th-stage larvae of different stages in the moult cycle gave some information about the power of the host to synchronize the graft to its own moult cycle. Transplantations between different larval stages showed that the grafted integument responded to the hormonal milieu of the host. Adult integument was transplanted onto larvae to study the reversal of metamorphosis. It was found that the development of a supernumerary population of hairs depended on the integument passing through a moult cycle in the presence of JH. After two moults in the presence of JH, reversal of metamorphosis was found to vary over the surface of the transplant, being further advanced at the margin. At the edge of the graft properly formed larval bristles developed, while at the centre adult hairs were formed in adult cuticle. Intermediately formed bristles were found in the intervening areas. It is suggested that reactions associated with wounding are the cause of this heterogeneous result. The significance of these results in relation to other work and to theories concerning the mode of action of the juvenile hormone is discussed.
The Thermal Dependence of the Rates of Glycogen and Triglyceride Synthesis in the Mosquito
Authors: Van Handel Emile 
Published: April 2021

ABSTRACT
In poikilothermic animals the dependence on temperature of physiological processes such as growth, respiration, heart-beat, wing-beat, motility, etc., has been studied, but no information seems to be available for the temperature dependence of the synthesis of a defined product. An opportunity to measure rates of synthesis of specific products, namely, the accumulation of caloric reserves, is offered by the female mosquito. When mosquitoes are starved they catabolize all glycogen and triglycerides; after subsequent feeding on a single, measured meal of sugar, quantitative relations can be established between this precursor and its products, the new glycogen and triglyceride pools (Van Handel, 1965 a). In the present investigation, this biological technique has been used to determine the velocity with which these two products accumulate at different temperatures.
The Function of Haemoglobin in Relation to the Maintenance of Neutral Buoyancy in Anisops Pellucens (Notonectidae, Hemiptera)
Authors: Miller P. L. 
Published: April 2021

ABSTRACT
The percentage saturation of the haemoglobin of the intact water bug, Anisops pellucens, in equilibrium with various ambient oxygen tensions has been determined. From this an approximate dissociation curve for the pigment and a P50 value of 28 mm. Hg at 24 ° C. have been obtained. Anisops haemoglobin shows no Bohr effect, but appears to be very temperature-sensitive. During free dives the haemoglobin is regularly de-oxygenated ; the oxygen so derived probably helps to maintain the bug in neutral buoyancy for much of each dive. Carbon monoxide has been used to inactivate the haemoglobin, after which dives are reduced to about one-fifth of their normal duration and the phase of neutral buoyancy is abolished. Much of the oxygen which leaves the pigment probably diffuses into the ventral airstore and then re-enters the tracheal system via the thoracic spiracles. External ‘pumping’ movements may serve to speed this gas migration. It is argued that physical gill action plays a negligible part in the normal respiration of this species.
Activity of Interneurones in the Arm of Octopus in Response to Tactile Stimulation
Authors: Rowell C. H. Fraser 
Published: April 2021

ABSTRACT
A method for recording nervous activity from the nervous system of the arm of Octopus is given. Difficulties of mobility and vasoconstriction are reduced by brain lesions. Three areas were recorded : afferent sucker nerves, axial ganglia, and the dorsolateral axial cord. The sucker nerves include large tactile units corresponding to discrete parts of the sucker rim. These are fast-adapting, phasic, not very sensitive, and are located in the area of motor innervation of the same nerve. Two types of interneurones were found in the axial ganglia, responding to either tactile stimulation of their own or neighbouring suckers, or to proprioceptive input from their own sucker. Motor units to the sucker musculature were also found. Almost all recorded units in the dorsolateral axial cord were interneurones receiving tactile input. They have the following characteristics :
they are rapidly adapting, often phasic, and show little or no ‘spontaneous’ activity. they habituate rapidly to even complex patterns of stimulation and discriminate between them, behaving as ‘novelty units’. different sites of stimulation are discriminated by change in both the number of active units and their temporal patterning. The smallest area shown to be separately represented is the rim of one sucker. prolonged activity can be initiated by a brief initial stimulus, which is without apparent correlated motor output. stimulation of areas outside a unit’s sensory field can lead to activity in that unit or to dehabituation in a previously active unit.
No proprioceptive representation was found.
Respiratory Response to Experimentally Induced Anaemia in the Pinfish (Lagodon Rhomboides)
Authors: Cameron James N. , Wohlschlag Donald E. 
Published: April 2021

ABSTRACT
Injection of phenylhydrazine hydrochloride produced surviving pinfish with as low as 0·26 g. % haemoglobin (2·9% of the normal value). Haematocrits dropped as low as 1–2%, against a normal value of about 30%. Measurements of resting metabolism showed no significant difference related to haemoglobin level, but anaemic fish were slightly higher. Tolerance times at low oxygen levels were not clearly related to haemoglobin levels. Cardiac rates show a compensatory increase in response to haemoglobin reduction which accounts for about 50% of the predicted increase in cardiac output. Haemoglobin is thought to provide a reserve capacity in circulatory ability for oxygen transport through its influence on cardiac output. The reserve capacity is important in meeting unusual demands of migration or escape, and may prove useful in comparing different species.
Free Amino Acid and Haemolymph Concentration Changes in Sphaeroma Rugicauda (Isopoda) During Adaptation to a Dilute Salinity
Authors: Harris R. R. 
Published: April 2021

ABSTRACT
Non-protein and protein nitrogen fractions of the isopod Sphaeroma rugicauda were measured in animals adapted to 100 and 2% sea water. The non-protein nitrogen component was reduced in animals acclimatized to the lower salinity. Free amino acids accounted for 88 and 74% respectively of the non-protein nitrogen in the two salinities. In 2 % sea water taurine, proline, glycine, alanine and glutamic acid showed the greatest decreases in concentration compared to the levels measured in animals adapted to 100% sea water. The decrease in total free amino acids of animals acclimatized to 100% sea water and transferred to 2% sea water was measured. The total free amino acid concentration is reduced to the 2% sea water level within 12 hr. after transfer. Free amino acid, haemolymph sodium and total body sodium levels after transfer to 2% sea water were compared. The asymmetry between the fall in haemolymph sodium concentration and the decrease in total body sodium under these conditions is thought to be due to a water shift from the haemolymph into the tissues. It is suggested that the osmotic pressure of the cells falls at a slower rate than that of the haemolymph.
Locust Wind Receptors
Authors: Camhi Jeffrey M. 
Published: April 2021

ABSTRACT
The sensory cell innervating each wind-receptor hair on the face of the desert locust responds to wind with a slowly adapting train of impulses. Each sensory cell responds maximally to wind flowing in a specific direction. The optimal direction for any sense cell is the same as the angle of curvature of its hair shaft. The optimal wind direction has been determined for each sensory cell of the organ. Three independently measured factors determine a sense cell’s direction response : drag asymmetry of the curved shaft, elastic force asymmetry of the socket, and the eccentric attachment of the dendrite. The sensory cells probably continue uninterrupted through the brain, synapsing first in the suboesophageal ganglion. An accessory neurone of unknown function and unidentified central connexions links each seta with the prothoracic ganglion.
The Nitrogen Balance in Plaice, Sole and Perch
Authors: Birkett L. 
Published: April 2021

ABSTRACT
Plaice, sole and perch were fed on live food for 20−40 days, and their growth rates were compared with their rates of absorption, both measured as mg. N/g. live weight/day. The gross efficiency of nitrogen conversion—that is, the growth per unit of nitrogen absorbed in excess of maintenance—was between 27·5% and 49·0% The maintenance rate of absorption was between 0·173 and 0·499 mg-N/g./day. The basal rate of excretion amounted to 0·056−0·208 mg. N/g./day. At maintenance, total excretion is equal to the amount of nitrogen absorbed from the food. The metabolic cost of growth was 1·04−2·64 mg. N excreted per mg. N retained.
Effects of Various Ions on the Resting and Active Membrane of the Somatic Muscle of the Earthworm
Authors: Hidaka T. , Ito Y. , Kuriyama H. , Tashiro N. 
Published: April 2021

ABSTRACT
The properties of the membrane, in both the resting and the active state, of the longitudinal muscle of the earthworm were studied under various ionic environments. The maximum slope of the membrane potential change against a tenfold change in the external potassium concentration was 27 mV. in the presence of external sodium and 42 mV. in the absence of external sodium. In the normal external potassium concentration the removal of sodium hyperpolarized the membrane from a normal resting potential of – 36 to – 58 mV. Reduction of the external calcium concentration to a tenth of its normal value depolarized the membrane by about 16 mV. In excess of external potassium the spike height and the after-hyperpolarization were decreased and the duration of the spike was prolonged. In sodium-free solution spikes with an overshoot potential were generated both spontaneously and under the stimulus of an intracellularly depolarizing current. The amplitude and the maximum rate of rise of the spike were dependent on the external calcium concentration, whether or not sodium was present externally. Manganese modified the membrane activity by competition with calcium.
The Effect of Splitting part of the Brain or Removal of the Median Inferior Frontal Lobe on Touch Learning in Octopus
Authors: Wells M. J. , Young J. Z. 
Published: April 2021

ABSTRACT
Octopuses with the whole supraoesophageal lobe divided in the mid-line show a lesser preference for smooth objects than normals. Learning of a simple successive tactile discrimination can proceed as fast in such a half-brain as in a whole brain. Animals in which the anterior part of the supraoesophageal lobe alone was split also learned approximately as fast as normals. When tested on the untrained side they showed at most slight signs of ‘transfer’. The unsplit vertical lobe system apparently mediates little transfer, either of learning to take or not to take an object. Animals with the posterior part of the supraoesophageal lobe alone split learned less well than normals or those with anterior splits, the deficit being due to the large number of takes of the negative object. Tests on the untrained side showed that good transfer of the capacity for positive and negative learned response occurred through the intact inferior frontal commissures. Animals without the median inferior frontal lobe showed a marked preference for rough objects. Of six trained with smooth positive only two showed increasingly correct discrimination. Four out of seven animals trained with rough positive showed an increasingly correct performance as a result of training. The performance of the others got worse as training proceeded. It is not clear whether this learning deficit is due to the excessive rough preference or to the absence of some part of the learning mechanism owing to removal of the median inferior frontal lobe. Tests on the untrained side of animals without median inferior frontal show no capacity to discriminate. This shows that the median inferior frontal is vital to lateral transfer and confirms that learning cannot readily be transferred through the vertical lobe system.
An active Reduction of Water Level in Insect Cuticle
Authors: Winston P. W. , Beament J. W. L. 
Published: April 2021

ABSTRACT
The water in cuticles excised from living cockroaches and locusts is not in osmotic equilibrium with their blood. It represents on average an osmotic pressure 15 atmospheres greater than the blood osmotic pressure. In the locust a cuticle in equilibrium with the blood would contain 60% more water. This is cited as evidence for the continuous expenditure of energy by the epidermal cell in regulating the water balance of the cuticle.
Muscle Co-Ordination of the Respiratory Pump of the Carp (Cyprinus Carpio L.)
Authors: Ballintijn C. M. 
Published: April 2021

ABSTRACT
An analysis has been made of the pattern of activity of the muscles of the head of the carp, in relation to respiratory movements and pressures generated in the buccal and opercular cavity, during normal respiration and during coughing. From comparison with the results of analyses carried out on other species of fish it is suggested that the respiratory movements of free-swimming teleosts in general conform to the following principles: the lateral expansions and contractions of the buccal and opercular cavities are always synchronous, but the lowering of the floor of the mouth may be synchronous with, or may precede, the lateral expansion. In the carp the levator operculi muscle, although it inserts on the opercular bone, does not participate in the opercular pump but is the abductor of the lower jaw.
Movement Pattern and Efficiency of the Respiratory Pump of the Carp (Cyprinus Carpio L.)
Authors: Ballintijn C. M. 
Published: April 2021

ABSTRACT
A study of the function of the respiratory muscles is made by influencing the respiratory movements artificially (keeping jaw or opercula open or closed) and analysing the compensatory changes in muscle activity. The differential pressure curves during experiments with mouth and opercula open or closed confirm that the buccal and opercular pump are alternately effective. The respiratory efficiency of the pumps, in terms of both constancy of the water flow over the gills and volume output, decreases if the mouth opens before the transition from compression to expansion of the cavities (as is realized in the trout) and increases if it opens later. In the carp lower jaw abduction occurs at the same time as the transition. An electric analogue of the respiratory pumps has been constructed. It confirms the opinion that the respiratory pressure curves of fishes are generated by a double pump with in-phase cavity movements. Further, it demonstrates that the efficiency of the pumps is greater if lower jaw abduction is synchronous with the onset of cavity expansion (carp) than if it is earlier (trout). The efficiency, however, is shown to be maximal if the mouth opens slightly later.
Histological and electrophysiological Studies On The Giant Axons Of The Cockroach Periplaneta Americana
Authors: Spira M. E. , Parnas I. , Bergmann F. 
Published: April 2021

ABSTRACT
Nerve cords of the American cockroach were cut between the 5th and 6th abdominal ganglia. All giant axons degenerated in the abdominal regions and were present but collapsed in the thoracic connectives. Unilateral lesions permitted identification of ventral giant axons all along the nerve cord. 4. The diameter of abdominal giant axons descreases progressively from 60µ at the metathoracic ganglion to 7 µ at the suboesophageal ganglion. 5. It is concluded that abdominal giant fibres do not synapse at the thoracic ganglia but form narrow isthmuses. 6. The tapering of the giant fibres in the thoracic nerve cord may be responsible for the sequence of nicotine blockade from rostral to caudal regions.
Non-Homogeneous Conduction In Giant Axons Of The Nerve Cord OfPeriplaneta Americana
Authors: Parnas I. , Spira M. E. , Werman R. , Bergmann F. 
Published: April 2021

ABSTRACTStudies with intracellular electrodes show that the abdominal giant axons of the cockroach give ascending responses to stimulation of cereal nerves and descending responses to stimulation of S0–T1 connectives. In the thoracic region one or more areas of low safety factors occur for descending conduction. These areas, which are considered not to be synapses, are blocked by low doses of nicotine (2-5 µg./ml.) fatigued by repetitive stimulation and show conduction delays of 0·6—0·7 msec. It is concluded that the abdominal giant axons extend continuously from to suboesophageal ganglion. The possibility of bi-directional conduction under physiological conditions is discussed.
Asymmetric Flagellar Movement in Relation to the Orientation of the Spore Of Blastocladiella Emersonii
Authors: Miles C. A. , Holwill M. E. J. 
Published: April 2021

ABSTRACT
The translational and turning movements of the spore of Blastocladiella emersonii are described. The turning movement appears to be a direct result of asymmetric flagellar activity. The results indicate that co-ordination of propagated waves may not be exclusively effected by a system which involves the mechanical properties of the flagellum but also by stimuli derived from another source.
The Production of Cuticle Wax by Engorged Females of the Cattle Tick, Boophilus Microplus (Canestrini)
Authors: Cherry Lois M. 
Published: April 2021

ABSTRACT
Weight of cuticle wax produced by the engorged female cattle tick, Boophilus microplus (Canestrini), and loss of body weight during egg production, have been measured at intervals between dropping from the host and completion of egg laying. Wax increased in weight from 20 to 63 µg. per tick between 6 and 222 hr. after dropping. This increase took place in two stages, with the steepest increase between 6 and 54 hr. and a smaller increase between 78 and 150 hr. Body weight fell by 71 % between 6 and 222 hr. The rate of loss was highest during early egg production, reaching its peak on the fourth day after dropping. The most rapid increase in weight of cuticle wax took place before the onset of oviposition. During peak egg production the increase was slight. During the decline of egg production cuticle wax increased slowly in weight. The possible physiological function of the increased wax secretion, and its relation to general metabolic activity, are discussed.