bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionic Regulation in the Palaemonid Prawn Palaemon (=Leander) Serratus
Authors: Parry G. 
Published: April 2021

ABSTRACT
Analyses have been made of the blood and urine of Palaemon serralus for the inorganic ions Na, K, Ca, Mg, Cl, SO4, the animals being kept in 50, 100 and 120 % sea water. When the animal is in 100 % sea water the concentrations of ions in the blood, expressed as percentages of their concentrations in the medium (to the nearest 5 %) are as follows: Na, K and Cl, 85%; Ca, 105%; Mg, 20%; SO4, 10%. When the animal is in 50% sea water the corresponding figures are: Na and Cl, 105%; K, 120%; Ca, 200%; Mg, 20%; SO4, 10%. When the animal is in 120% sea water the corresponding figures are: Na, K and Cl, 85 % ; Ca, 115%; Mg, 30 % ; SO4, 20 %. The concentrations of Na, K and Ca in the urine are always slightly ( 20 %) less than their concentrations in the blood. The concentration of Cl is slightly greater in the urine than in the blood (10-20 %) and the concentrations of Mg and SO4 are very much greater, by factors of up to 7 times. The relative concentrations of ions in blood and urine do not change substantially with changes in the external medium. The antennal gland, although it plays no part in purely osmotic regulation, is no doubt partly responsible for maintaining the low blood concentrations of Mg and SO4.
Observations On the Respiratory Physiology and On the Haemoglobin of the Polychaete Genus Nephthys, With Special Reference to N. Hombergii (Aud. Et M.-Edw.)
Authors: Jones J. D. 
Published: April 2021

ABSTRACT
Littoral representatives of the genus Nephthys are described as burrowing forms, able to irrigate their burrows with well-aerated sea water except when the sand is exposed by the tide. Then they are sealed in and have no access to oxygen outside the sand. The concentration of dissolved oxygen in the sand water corresponds to a tension of about 7 mm. of Hg compared with a value about twice as great in the residual water in Arenicola burrows. Extracellular pigments in the blood and coelomic fluid of Nephthys spp. are characterized as haemoglobins. The quantity of these pigments is shown to be inadequate as an oxygen store for the exposure period. Dissociation curves for both pigments from N. hombergü are found to be approximately hyperbolic and the oxygen affinities relatively low. The significance of the difference in oxygen affinity and the direction of the Bohr effect, between the vascular and coelomic pigments cannot yet be evaluated. It is suggested that the Nephthys pigments are unspecialized and may function as a high-tension oxygen transport system only when the sand is covered by the sea. This is contrasted with the possibility of low-tension oxygen transport by the haemoglobin of Arenicola.
Some Temperature Responses of Nymphs of Locusta Migratoria Migratorioides (R. & F.), With Special Reference to Aggregation
Authors: Chapman R. F. 
Published: April 2021

ABSTRACT
The results of experiments in a temperature gradient showed a definite temperature ‘preference’ on the part of hoppers (nymphs) of all stages. This ‘preference ‘was constant from instar to instar but varied with the preconditioning temperature. The rate of movement of first-instar hoppers was shown to increase in a linear manner with temperature up to 25°C., above which the rate fell off. It is suggested that these are quantitative data supporting Kennedy’s (1939) remarks on negative thermokinesis. Experiments in 12 1. cages showed that group formation depends on a patchy temperature field rather than on any particular temperature, and that environmental conditions are more important than mutual responses of the hoppers. Hoppers less than 3 days old, as well as older ones, formed groups under the conditions of patchy temperature. The experiments suggested that surface temperatures are more important than air or body temperatures in the initial formation of groups. Basking groups induced by local radiant heat in a large cage did not differ in form from the groups in the 12 1. cages formed in the absence of radiant heat. Surface texture was shown to be unimportant in group formation, hoppers always collecting on the hotter surface even when temperature differences were of the order of only 1° C. The groups were shown to be in a very dynamic state, with hoppers continually coming and going. The average time spent in a group by any one hopper was 6 min. 46 sec. Formation of basking groups in the field depends on the physiological state of the hoppers, rather than on any definite temperature.
Homing Orientation in Pigeons in Relation to Opportunity to Observe the Sun Before Release*
Authors: Pratt J. G. , Thouless R. H. 
Published: April 2021

ABSTRACT
A total of ninety-six single releases of pigeons was made over distances varying from 48 to 238 miles. The birds were transported under cover which prevented them from seeing the landscape or the sun. It was generally their first release from a point out of sight of the loft. The vanishing points (as observed through field-glasses) from all releases combined showed a significant tendency to be in the homeward half of the circle. The direction of the bird from the release point was observed at various intervals of time from 10 sec after release. There was a statistically significant relationship between the direction at 10 sec and that at 40 sec (or 60 sec.), and the latter directions were closely related to those of disappearance. To test the hypothesis that correct orientation depends on an interval of time for observing the sun’s motion, some birds were allowed to see the sun for some time before flight, while others were kept in shadow. Even after the short interval of 10 sec., the no-sun birds showed no less accuracy of orientation than did the sun birds. In two releases the pigeons showed a consistent choice of direction not within the home half of the circle. This suggests the need for caution in drawing conclusions based on few release points, and the desirability of using many release points and taking the average orientation at each as the statistical unit. Our results strongly suggest that there is no difference between the orientation of pigeons that have and pigeons that have not seen the sun before release. This conclusion is, however, tentative until it is confirmed by further experiments using a larger number of release points.
The Behaviour of Anodonta Cygnea L., and Its Neurophysiological Basis
Authors: Barnes Gordon E. 
Published: April 2021

ABSTRACT
Anodonta cygnea L. in captivity exhibits rhythmical behaviour as follows: Periods of activity and quiescence alternate, with frequencies varying with different specimens from 3 to 30 per week. During the periods of quiescence the shell valves are completely adducted. During active periods the valves normally gape. (The ‘slow’ rhythm.) During the active periods the adductor muscles show frequent rapid contractions followed by slow relaxations. This activity is also rhythmical, and has a frequency of up to 20 per hour. (The ‘rapid’ rhythm.) The neuromuscular mechanism of these rhythms has been investigated, and it is shown that : (a) both adductor muscles participate in the rhythms ; (a) the slow rhythm is a function of the unstriated portions of the muscles ; (c) the rapid rhythm is a function of the striated portions of the muscles ; (d) the rapid rhythm in each adductor muscle is controlled by its nearest ganglia; (e) the slow rhythm in each adductor muscle is controlled by the combined effect of the nearest ganglia, which tend always to produce a tonus, and the cerebropleural ganglia, which at intervals inhibit that tonus; (f) the control of the rhythms appears to be intrinsic in the nerve ganglia, and independent of peripheral stimulation. The effect of morphine hydrochloride on Anodonta has been investigated, and it is shown that, in addition to a possible narcotic effect, it abolishes the tonus of the unstriated portions of the adductor muscles. A reflex is described which leads to the relaxation of the tonus in the adductor muscles, and the commencement of a new period of activity. The stimulus is vibration and/or rotation. On the basis of the above conclusions regarding Anodonta a hypothesis is put forward to account for certain facts about the contraction and relaxation of the adductor muscles of Mytilus.
The Excretion of Sodium, Potassium and Water by the Malpighian Tubules of the Stick Insect, Dixippus Morosus (Orthoptera, Phasmidae)
Authors: Ramsay J. A. 
Published: April 2021

ABSTRACT
The excretion of sodium, potassium and water by the Malpighian tubules of the stick insect has been further studied in preparations of single tubules isolated in droplets of medium under liquid paraffin. There is some gradation of physiological activity along the length of the superior tubule. Sodium, potassium and water are secreted into the tubule at all levels, but the sodium/potassium ratio is greater in the proximal region. The proximal and middle regions of the inferior tubule have not been shown to differ in any way from the corresponding regions of the superior tubule. The distal dilatation has quite different properties and does not produce urine. The rate of urine flow increases markedly as the potassium concentration in the medium is increased; the corresponding effect of sodium is barely detectable. Sodium, like potassium, can be actively transported against an electrochemical gradient, and does not appear to compete with potassium in the secretory mechanism. The rates of secretion of sodium and potassium vary in direct proportion to the respective concentrations of these ions in the medium. The rate of secretion of potassium is more than ten times greater than that of sodium.
An Investigation of Homing Ability in Pigeons Without Previous Homing Experience
Authors: Pratt J. G. 
Published: April 2021

ABSTRACT
Three different groups of pigeons were given homing releases, the first at 143 miles and the other two at 75 miles. Approximately half of the birds (untrained group) had made no homing flight before they were released in the long-distance test. The others (trained group) had been released 3 times in different directions at 10 miles from the loft in one experiment and at 2 – 3 miles in the other two. Both the trained and untrained birds showed a statistically significant tendency to vanish from sight at the release point in the homeward half of the circle, which confirms Matthews’s results with untrained pigeons. There was no appreciable difference in homing success and speed between these two groups. More than 50 % of each group homed, while Matthews had only one out of thirty-nine untrained birds return to the loft. The untrained birds were released ahead of the trained birds in each experiment. In the third experiment, two untrained birds homed, separately, without being overtaken by any trained birds. Thus these two birds showed clearly that pigeons without previous homing experience could and would complete a longdistance flight to the loft unassisted. Subsequent tests in which only untrained birds were released have confirmed this finding. Birds differing in both age and stock were compared in the second and third experiments. Within the range of 4 – 9 months, age was not found to be a factor in homing behaviour. Stock or the hereditary factor, however, was found to be related to success in regaining the loft, though it did not appear to influence the accuracy of orientation shown by the departure flights. There is a suggestion that the height of the release point influences the immediacy of departure. Birds set free from the top of a 100 ft. tower vanished more quickly than pigeons released on the ground.
Observations on Luminescence in Renilla (Pennatulacea)
Authors: Nicol J. A. C. 
Published: April 2021

ABSTRACT
Luminescence is well known in three groups of coelenterates, viz. Hydrozoa, Scyphozoa and Alcyonaria (literature reviewed by Harvey, 1952). Of these Pelagia, Pennatula and Renilla have been most intensively investigated. Observations indicate that in all these forms, light emission is under nervous control. Mechanical and electrical stimulation gives rise to a wave of light which passes over the surface of the animal (the disk in medusae, or the surface of the colony in hydroids and alcyonarians), at a rate which is consonant with nervous transmission as deduced from the spread of excitation concerned with muscular contraction. In his pioneering studies of the physiology of luminescence, Panceri (1872 a, b) found that localized stimulation of Pennatula excites luminous waves which spread up and down the colony, according to the position of excitation. Simultaneous excitation of the two extremities of an animal gives rise to two converging waves which cancel out on meeting. Parker’s (1920b) detailed study of Renilla, which will be referred to later, showed that luminescence is controlled by a nerve net, and that cuts made in any direction through the rachis still permit excitation to be transmitted so long as the stimulated region is not completely isolated, i.e. the nerve net is non-polarized.
A Simple Procedure for the Study of Ionic Regulation in Small Animals
Authors: Shaw J. 
Published: April 2021

ABSTRACT
A simple procedure is described for the estimation of sodium, potassium, calcium and magnesium in quantities of about 1 µg. The ions are precipitated by specific chemical reagents, the precipitates separated by centrifugation and converted quantitatively into chlorides. The chloride is titrated by the Volhard method or by an electrometric method using a simple automatic micro-burette.
Measurements made on simple salt solutions and on blood samples gave standard deviations of 1-2% except in the sodium method where the error was greater (2-4%).
A Study of the Blood Groups of the Rabbit, with Reference to the Inheritance of Three Antigens, and the Agglutinability of the Red Cells Carrying Them
Authors: Joysey Valerie C. 
Published: April 2021

ABSTRACT
Kellner and Hedal’s antigen G is identical with Heard’s antigen Z, and similarly g with Y. Kellner & Hedal’s (1953) conclusion that all rabbits must possess at least one of the antigens G or g was found not to be true of animals in this stock. Animals lacking both antigens were found to possess Heard’s antigen W. Z, Y and W form an allelomorphic trio. Heard’s evidence strongly suggests that the most agglutinable cells have more antigen sites (for the antibody in question), than less agglutinable cells. Evidence provided here shows that in the case of the Z and Y antigens homozygous cells are more agglutinable than heterozygous cells, and therefore probably have more sites of the Z or Y antigens respectively. Also the number of Y antigen sites is greater in Y Z than in Y W cells. It was not possible to demonstrate a similar difference for Z between Z Y and Z W cells. It is suggested that the notation of this allelomorphic trio in rabbits should be standardized as follows : Ga= Kellner & Hedal’s G and Heard’s Z; Gb = Kellner & Hedal’s g and Heard’s Y; Gc=Heard’s W.
Photo-Kinesis in the Ammocoete Larva of the Brook Lamprey
Authors: Harden Jones F. R. 
Published: April 2021

ABSTRACT
Ammocoetes show no inherent rhythm of locomotory activity to parallel that demonstrated for their melanophores. They react ortho-kinetically to light above a threshold lying between 5.4 and 54m.c. Ammocoetes collect in the dark end of a light gradient at intensities below the threshold for ortho-kinesis. A klino-kinesis would appear to be the mechanism by which this aggregation is accomplished. All the evidence points to the conclusion that the locomotory reactions of the ammocoete to light bears no directional relationship to the source of stimulation and that they are entirely at random.
Wax Secretion in the Cockroach
Authors: Beament J. W. L. 
Published: April 2021

ABSTRACT
The production of massive quantities of waxy materials by bees and similar insects has been known for a very long time, but it was not until 1938 that Bergmann showed the existence of smaller quantities of wax in the cuticle of Bombyx. Ramsay (1935) was the first to demonstrate that a greasy material on the surface of the cuticle was responsible for waterproofing the cockroach, and subsequently the work of Wigglesworth (1945) and Beament (1945) produced evidence for believing that the existence of a thin layer of wax in the epicuticle was widespread throughout the insects, and was the chief mechanism for restricting water-loss. It is now known that wax layers are also present in ticks (Lees, 1947) and in many arthropod eggshells (Beament, 1946, 1951, etc.), while Chibnall, Piper, Pollard, Williams & Sahai (1934) have carried out a detailed analysis of beeswax and of the wax of the white pine chermes. These waxes consist of long chain alcohols, paraffins and acids ; the aliphatic chains always appear to be saturated. The similarity of the physicochemical behaviour of cuticular waxes with beeswax, as outlined by Beament (1945), seems to leave little doubt that the minute but essential amounts of wax in typical insect cuticle are composed of the same type of chemical components as those found in beeswax. The range of melting-points of these materials shows that relative changes in the chain length of the component would be sufficient to account for the differences between the specific properties of waxes derived from different species.
The Nerves and Muscles of Medusae
Authors: Horridge G. A. 
Published: April 2021

ABSTRACT
The responses of Geryonia proboscidalis to electrical and mechanical stimulation have been studied with particular attention to the transmission of excitation. There are two kinds of excitation transmitted across the undersurface of the bell; first, the symmetrical beat is co-ordinated by an isotropic conducting system which acts in a through-conducting, all-or-nothing manner, and produces brief contractions of the circular muscle; secondly, the movements of the manubrium are co-ordinated by a radial conducting system, which produces a maintained contraction of the radial muscles of the manubrium. The independence of these two conducting systems is shown by the simultaneous and yet distinct transmission of the two kinds of excitation in different directions. The contraction wave is not transmitted through the ring nerves faster than over the rest of the bell. The manubrium bends towards a stimulated tentacle, and all the tentacles contract simultaneously, co-ordinated by a through-conducting pathway in the marginal nerve. There is evidence that a polarized pathway carries excitation from this system to the rhythmical marginal centres. Observations of Geryonia held with the axis horizontal show that the steering action is due to an asymmetrical maintained contraction of the velum. The known histological details of the nervous system are compared with the physiological pathways demonstrated by experiment. The differentiation of a primitive isotropic nerve net into distinct tracts with separate functions is essential for the several rapid feeding and swimming activities.
The Behaviour of Barnacle Cyprids in Relation to Water Movement Over A Surface
Authors: Crisp D. J. 
Published: April 2021

ABSTRACT
The velocity gradient of the fluid close to the solid boundary is the most appropriate description of the conditions of water flow which affect the attachment of the larvae of sessile forms to solid objects. The nominal speed of the water movement past the object is of importance only in so far as it influences the velocity gradient in the boundary layer. Experiments in glass tubes on cypris larvae of Elminius modestus and Balanus balanoides show that moderate velocity gradients exceeding 500 sec.-1 sweep the cyprids past the surface before they can attach. For large objects exposed to turbulent flow, the critical velocity gradient corresponds very approximately to a flow of 1-2 knots. Attachment under conditions of water flow is accompanied by negative rheotaxy, and can occur equally in the light and in the dark. Maximum attachment occurs at or below velocity gradients just great enough for the cyprid to be able to maintain position by swimming along the surface against the current. Once the cyprid has attached it cannot be pulled off the surface even by gradients greatly in excess of those which prevent attachment. Cyprids can migrate in all directions when exposed to moderate gradients, but they do so only with difficulty when the velocity gradient is high, particularly if the water is flowing in the same direction as that in which the cyprids are walking. The direction in which the cyprid migrates is altered only momentarily by changes in the direction of the current, the animal actively resisting the redistribution of forces acting on it. No direct evidence is given in this paper on the influence of water currents on fixation, but a critical comparison with other published work suggests that fixation can occur in places where the velocity gradients are greater than those which limit attachment, provided the cypris is able to migrate there after attachment. Moderate velocity gradients have little effect on the orientation at metamorphosis. Individuals tend to settle with the anterior end pointing downstream rather than in any other position. This orientation is the opposite from that which would be expected if the cyprid were passively orientated by the water current, but is likely to make subsequent feeding more efficient. The ability to attach under conditions of water flow, and the tendency not to attach under stagnant conditions, may have an important influence on the animals’ distribution and survival. Solid particles in suspension may profoundly influence the behaviour, hence the results given in this paper may not be relevant to conditions where scouring takes place.
Nervous Regulation of Luminescence in the Sea PansyRenilla Kollikeri
Authors: Nicol J. A. C. 
Published: April 2021

ABSTRACTLuminescence has been studied in the sea pansy Renilla kôllikeri, by means of photo-electric recording, and the mode of nervous regulation investigated. The luminescent response is under control of a non-polarized nerve net and is subject to facilitation which occurs terminally, at neuro-photocyte junctions. Facilitation is analysed in detail, and a facilitation-decay curve presented (Fig. 3). Between successive bursts of stimuli, facilitation may persist for some 10 min. Certain response parameters were measured. Latent period is o-12 sec. ; the response lasts 1 sec., and maximal intensity is reached in 0-22 sec. Conduction speed is 9 cm./sec. at 16-17° C. The refractory period of the response, as determined by high frequency stimulation, is o-2 sec. It is affected by fatigue and increases under repetitive stimulation. Under repetitive and prolonged stimulation, the animal passes into a hyper-excitatory state and luminous waves continue to arise long after stimulation has ceased. Conditions affecting this post-stimulatory discharge are examined. Comparison of facilitatory processes in quick muscular responses of sea anemones and luminescent responses of sea pens shows that they are essentially similar. From visual observations it appears that facilitation operates by recruitment of photocytes. Luminescence is of sporadic occurrence among coelenterates, and has been independently evolved on many occasions. It is suggested that its mode of regulation has been determined by the characteristics of the nerve net primarily concerned with control of muscles.