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1. 1. Crayfish were acclimated to fresh water and three dilutions of sea water for 4 days. Tissue acclimation was tested by studying the responses of the heart to different strengths of van Harreveld's at the end of this time. 2. 2. Hearts of animals acclimated to the more concentrated media were more tolerant of 2 × van Harreveld's than fresh-water hearts but were less tolerant of 1 × van Harreveld's. 3. 3. Results indicate that the animal is capable of cellular osmotic regulation when exposed to more concentrated media than fresh water.

1. 1. Oxygen consumption, body temperature and evaporative water loss were measured at various ambient temperatures between 5–35°C while the chipmunks were running in a treadmill respirometer at 20, 30, 40 or 50 m/min. 2. 2. Body temperature increased with increasing ambient temperature but was independent of velocity of running except at an ambient temperature of 35°C. 3. 3. Oxygen consumption increased with velocity at a given TA to maximum levels which were dependent upon TA. 4. 4. Total dotVO2—resting dotVO2 (cost of running) showed that the heat produced by running partially substituted for that due to cold at high velocity, but at low velocity running the heat produced by running adds to that due to cold. 5. 5. The evaporative water loss was increased five to seven times over resting levels while the animals were running 20 m/min at ambient temperatures of 15, 30 and 35°C. 6. 6. At a given TA the thermal conductance of chipmunks was greater during activity than when at rest and increased curvilinearly with TA at a given velocity.

1. 1. The osmotic and ionic composition of the contents of the cloaca and large intestine of roosters was measured during dehydration and during salt and water loading. The urine moved from the urodeum retrogradely into the coprodeum and large intestine during all three types of osmotic stress, and the coprodeum and large intestine were therefore exposed to urine-feces contents with osmotic activities from 60 to 600 mOs and from 200 to 400 mOs respectively. 2. 2. The retrograde movement did not result in any difference in maximal and minimal osmotic and ionic composition between normally voided urine that had been stored in the intestine and cloaca and urine collected directly from the ureters during the three types of osmotic stress. 3. 3. During dehydration a limited resorption of NaCl and water was suggested by comparison of the cloacal output of NaCl and water with that of roosters in which the urine was collected from ureteral funnels.

1. 1. Metabolic-temperature curves show summer animals to have higher weight-specific oxygen consumptions at all acute temperatures. 2. 2. Metabolic-temperature curves of both species reveal the winter animals to be less dependent on temperature. 3. 3. Effect of experimental temperature was found to be statistically significant, but the metabolic-temperature curves of acclimated animals showed no consistent change with change in experimental temperature. 4. 4. Experimental temperature affects the seasonal response to salinity, shown by gill respiration rate, differently in the two species. 5. 5. Summer animals of both species show an increase in respiration rate as the osmotic gradient between blood and environment increases. Data obtained during the winter show little change. These data present indirect evidence which indicates that the gills are involved in regulating blood electrolytes. 6. 6. The regression coefficient of weight-specific oxygen consumption as a function of whole body weight was found to be similar in both species and to have a value of −0.169.

1. 1. Eleodes armata exhibited greater water loss than Cryptoglossa verrucosa at all temperatures and humidities. 2. 2. At low temperatures and humidities, water lost through transpiration predomated; at higher temperatures and humidities, a greater percentage was lost via quinone secretions. 3. 3. No uptake of atmospheric moisture was observed for either species, C. verrucosa exhibited a reduction in water loss with increased dehydration. 4. 4. The presence of intact elytra reduced water loss in E. armata. 5. 5. Resistance to desiccation in the two species was correlated with observations of their seasonal abundance and activities.

1. 1. When analyzed by two-dimensional paper chromatography, two principal pattern types are evident in venom samples of Bufo regularis from thirteen African localities. 2. 2. Samples from the type locality (Egypt), Nigeria, South Africa and certain Rhodesian and Kenyan localities are similar, and show greater than 86 per cent affinity. 3. 3. Samples from Uganda and some Kenyan and Rhodesian localities are of a second type, and show greater than 90 per cent affinity. 4. 4. Affinities between Type 1 and Type 2 localities are all less than 85 per cent.

1. 1. A green chromoprotein has been isolated from the ova of the limpet Patella coerulea . 2. 2. At neutral pH the protein had absorption maxima at 278, 390 and 630 mμ and an inflexion at 580 mμ. 3. 3. The absorption at 630 mμ varied with pH. It decreased on either side of pH 6·, and disappeared in the presence of urea. 4. 4. A yellow pigment solution with an absorption maximum at 385 mμ and an inflexion at 550 mμ was obtained from the purified chromoprotein. 5. 5. It is suggested that the chromoprotein has a yellow prosthetic group and that the chromophore responsible for absorption at 630 mμ and, therefore, for the green colour of the protein is the result of an interaction of the prosthetic group with the native protein.

1. 1. After acute dehydration Rattus norvegicus, Acomys cahirinus and Meriones crassus lost 18·6, 12·8 and 7 per cent of their body weight. The decrease in body water (g/100 g animal) was 21·0, 11·2 and 3·3 (mean figures). 2. 2. The relative changes in plasma volume due to dehydration were 34, 4·9 and 11 per cent respectively. Extracellular fluid volume decreased by 32, 0 and 18 per cent. 3. 3. T-1824 half-life in the blood system decreased during dehydration in R. norvegicus and M. crassus . In A. cahirinus T 1 2 increased. 4. 4. Sources of water loss during dehydration and possibility of capillary permeability changes are discussed.

1. 1. The course of light and dark adaptation in the compound eye of the worker honey-bee (Apis melliefera) has been followed by determining the energies necessary to produce retinal action potentials of equal magnitude. 2. 2. Light adaption is completed in a few seonds. Dark adaption is slower, requiring 10–15 min to finish; however, most of the recovery occurs in the first minute. 3. 3. The process of recovery is slower the longer period of light adaption. 4. 4. The rates of dark adaption of the ultraviolet and green receptor systems are similar.

1. 1. The effect of prolactin on osmotic influx of water into isolated gills of the marine threespine stickleback, Gasterosteus aculeatus L., form trachaurus, was studied by an in vitro technique. 2. 2. Prolactin or the solvent (0·6% NaCl) was injected into the gills via the heart and ventral aorta. Immediately after the injection the heart-gill preparation was isolated and incubated in Ringer solution for 30 min before the individual gill arches were isolated and studied in dechlorinated fresh water. 3. 3. Under this condition, prolactin significantly reduced the weight increase of the isolated gills. Thus, prolactin may reduce the osmotic influx of water into the gills of sticklebacks in fresh water.

1. 1. Methaemalbumin forms in relatively large amounts in amphibians, reptiles and anthropoid primates but not in fishes, birds and non-primate mammals. 2. 2. Methaemalbumin formation in primates reflects the modern concept of primate phylogeny and suggests that at least three mutational steps were involved in the evolution of anthropoid methaemalbumin from a basic mammalian type. 3. 3. Primate methaemalbumin may have evolved under selective genetic pressure resulting from a haemochorial type of placentation with its intimate contact of foetal and maternal blood circulations.

1. 1. The rates of oxygen consumption of six species of tropical sea urchins were determined. 2. 2. The oxygen consumption rates of three species of epifaunal, regular urchins were significantly higher than the rate of two infaunal, irregular species. 3. 3. Oxygen consumption rates of a cidarid species which lacks peristomeal gills were intermediates between the oher two groups.

1. 1. Physiological control of the tunicate heart is of particular interest in view of the importance of the phylogenetic position of this class. A new approach to this problem was made in this laboratory by obtaining the electrocardiogram of the tunicate heart (isolated within its pericardium) by means of a Grass oscillograph and a suitable amplifier system. 2. 2. The Ciona electrocardiogram was not necessarily correlated with visually observed movements of the myocardial endothelium; normal spikes, at 1/1·9 sec (28°C), can be obtained with relatively quiescent hearts, or hearts exhibiting partial beats. 3. 3. Acetylcholine, pilocarpine, physostigmine, quinidine and procaine had relatively little effect on spike frequency, but increased, particularly in the case of pilocarpine and procaine, spike duration. 4. 4. Epinephrine markedly increased cardiac rate, while digitalis restored spike amplitude and frequency in failing hearts.

1. 1. Nauplius larvae of the barnacle Elminius modestus Darwin were used to assess the toxicities of some primary, secondary and tertiary aliphatic amines and quaternary compounds. 2. 2. For the three series of aliphatic amines toxicity was largely determined by the concentration of the uncharged amine species 3. 3. With the exception of n-heptylamine, which is markedly time-dependent, studies on the time-dependence of toxic action indicated that the aliphatic amines occupied an intermediate position between chemically toxic agents (e.g. cupric ion) and typical physical narcotics such as amyl alcohol. 4. 4. At 30°C the ld 50 values for n-amylamine and n-decylamine were approximately half those obtained at 6°C. Over this same temperature range mercuric chloride showed a tenfold decrease in ld 50. 5. 5. Determinations of thermodynamic activity coefficients allowed evaluation of the thermodynamic activity at which the uncharged amine species exerts its physiological action. Where toxicity is largely determined by the concentration of this species the amines act at thermodynamic activities between 10−3 and 10−6, the primary amines being the most toxic. It is argued that the amines qualify as anomalous members of the group of physically toxic substances.

1. 1. Blood pH, p O 2 and p CO 2 values of the unanaesthetized tammar wallaby ( Macropus eugenii ) were determined at rest, and during moderate and severe heat stress. Values from anaesthetized animals were also obtained. 2. 2. Similarities between the resting values and normal eutherian values are discussed in relation to the lower metabolic rates of marsupials. 3. 3. The respiratory response of the tammar to heat was found to be similar to that of many eutherians. Exposure to moderate heat resulted in the respiratory rate increasing gradually until it stabilised at about 350 breaths/min. During severe heat stress the respiratory rate increased to higher values, and then decreased. The decrease in rate was similar to second-phase breathing as observed in some eutherians. 4. 4. No major changes were observed in the acid-base status of the blood, when the tammar was panting during moderate heat. However during second-phase breathing a respiratory alkalosis occurred, apparently due to the excessive alveolar ventilation.

1. 1. The non-protein nitrogenous substances of the tissues of the freshwater crayfish Astacus pallipes have been examined by chromatographic methods. 2. 2. About 80 per cent of the non-protein nitrogen of abdominal muscle and 70 per cent of the non-protein nitrogen of the hepatopancreas has been accounted for. 3. 3. With the exception of betaine all the non-protein nitrogenous substances found by Kermack et al. (1955) in tissues of the marine decapped Homarus vulgaris were found in the tissues of Astacus pallipes. 4. 4. The concentrations of non-protein nitrogenous substances were much lower in the tissues of Astacus pallipes than in the tissues of Hamarus vulgaris. 5. 5. The presence of phosphorylethanolamine and of glycerylphosphorylethanolamine in the hepatopancreas of Astacus pallipes is reported.

1. 1. The enzymes of the Embden-Meyerhof pathway and the initial reactions of the hexose monophosphate shunt were studied in cell-free preparations of the aquatic snail Physa halei Lea. 2. 2. Both glucose-6-phosphate dehydrogenase and 6-phosphogluconic dehydrogenase were demonstrated and found to resemble the mammalian enzymes in co-factor specificity. The presence of these two enzymes suggests a functional hexose monophosphate shunt in P. halei. 3. 3. Measurements on the glycolytic enzymes, phosphoglucomutase, phosphoglucoisomerase, aldolase, triosephosphate isomerase, α-glycerophosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglyceric kinase, phosphoglyceric mutase, enolase, phosphopyruvic kinase and lactic dehydrogenase are presented. Most of the enzymes have characteristics that are similar to mammalian enzymes, however, aldolase was found to be sensitive to cyanide and lactic dehydrogenase functions as well with NADP as with NAD.

1. 1. Cathepsin-type activity of homogenates of Locusta migratoria migratorioides eggs is reported. 2. 2. Cleavage of haemoglobin was optimal at pH 3·5–4·1. 3. 3. Activity was related to age of eggs after oviposition and to embryonic stages. 4. 4. Occurrence and possible role of cathepsin-type enzymes in insects and in their eggs are discussed.

1. 1. Rainbow trout, Salmo gairdneri (112yr old), were acclimated to a daily temperature cycle ranging from 8 to 18°C. 2. 2. Control fish were maintained at constant temperatures which coincided with sample temperatures of the cycling fish. 3. 3. Sodium, potassium, chloride and water were measured in the plasma and muscle of all the fish. 4. 4. In most cases the plasma ion levels in the cycling fish did not exceeded those levels of the control fish which were held at low temperatures (8–10°C). 5. 5. There was a highly significant inverse relationship between the muscle potassium and the muscle sodium levels in the cycling fish.

1. 1. The water, sodium, potassium, chloride, calcium, magnesium, phosphorus, total sulphur, inorganic sulphur, copper, iron, iodine and nitrogen contents of the proboscis, collar, branchial, genital, hepatic and intestinal regions of the enteropneust Balanoglossus gigas (Fr. Muller) were determined. 2. 2. The chemical constitution of the mucus, faeces and skeleton was also determined. 3. 3. Iodine is accumulated in the dorsal side of the hepatic region, iron in the hepatic region, sulphur in the sub-region hepatic II, nitrogen in the genital and hepatic regions, chloride in the collar and branchial region, copper in the collar, phosphorus in the proboscis and hepatic region; sodium, calcium, potassium and magnesium are concentrated both at the anterior and posterior end of the animal. 4. 4. The skeleton has high concentrations of calcium and copper.

1. 1. A dense network of nerve fibres is described in the auriculoventricular junction of the Helix pomatia heart. 2. 2. The results of both light and electron microscopical analyses suggest to us that the system has a neurosecretory function. 3. 3. The significance of such a system is discussed.

1. 1. The literature dealing with the anatomy of the venom organ, the stinging behaviour and a number of properties of the paralysing venoms of solitary wasps has been summarized. 2. 2. The Terebrantes studied sting their prey at random. Most of the Aculeata reviewed sting into or in the direction of the central nervous system (CNS). However, a few species of Aculeata sting at random or at least not in the direction of the CNS. 3. 3. The range of species specificity of the venom seems to vary widely between different species of wasps. 4. 4. Species belonging to both the Terebrantes and the Aculeata may produce venoms causing either a long-lasting or a relatively short paralysis. 5. 5. All venoms studied at present cause a paralysis of the locomotion but have very little if any effect on the heart beat and the movements of the intestines. 6. 6. A few paralysing venoms have been studied in more detail. The venom of Microbracon hebetor Say specifically blocks the neuromuscular transmission in the somatic muscles. It especially affects the frequency of the miniature excitatory postsynaptic potentials and therefore is assumed to act at a presynaptic site. 7. 7. The chemical composition of the venom of Sceliphron caementarium (Drury) has been studied. It contains a great many different compounds. Which of these compounds possesses the paralysing activity is as yet unknown. 8. 8. Although Philanthus triangulum (F.) stings in the direction of the CNS, the main action of its venom is on the neuromuscular junction, where it acts at a presynaptic site.

1. 1. The sponge Verongia fistularis may owe its intense yellow-green color at a depth of 40 m in the ocean to fluorescence. 2. 2. When alcoholic extracts of Verongia fistularis are excited by light of wavelength 365 mμ, they fluoresce maximally in the range 470–484 mμ; when excited at 464 mμ, maximum emission is in the range 517–528 mμ. Maximum emission at 475 mμ is obtained by exciting frequencies in the range 368–374 mμ; at 520 mμ maximum emission is obtained when the exciting frequencies lie in the range 363–374 and 456–476 mμ. 3. 3. In sections prepared for histological study, the fluorescence is preserved by formaldehyde fixation, extracted by alcoholic fixatives (Carnoy, etc.) and quenched by Bouin's fixation. 4. 4. The fluorescent pigment is localized in the lamellar portions of the spongin fibers of Verongia fistularis . 5. 5. An alcoholic extract prepared from the northern intertidal sponge Halisarca dujardini displayed excitation and emission spectra similar to those shown by Verongia fistularis . 6. 6. The corals Montastrea cavernosa and Mussa angulosa fluoresce red at depths of 25–40 m under excitation from the ambient light.

1. 1. The neonate fowl responds to cold by greatly increasing its metabolic rate. 2. 2. Since little or no shivering can be detected in the day-old chick it is concluded that the chick is able to increase its heat production by non-shivering means. 3. 3. An injection of noradrenaline (300 μg/kg) causes a slight increase in the oxygen consumption of the neonate but has little or no effect at 1 or 3 weeks after hatching. 4. 4. A similar dose of adrenaline results in a 30 per cent increase in the oxygen uptake of the day-old chick. At 1 and 3 weeks the response is similar but a little less. The increased metabolism is maintained for more than an hour. 5. 5. Falls in the carbohydrate stores of the liver and muscle can be demonstrated in the cold-exposed day-old chick. There is no evidence of similar changes in the 19-day-old embryo. 6. 6. The possibilities of noradrenaline and adrenaline playing a role in the thermoregulatory response are discussed. It is concluded that there must be other thermogenic stimulants response for the increase in the metabolic rate of the cold-exposed neonate fowl.

1. 1. The cocoon protein of the braconid, apocrite, hymenopteran Macrocentrus thoracicus has been analysed for amino acids. 2. 2. The amino acid composition confirms that the cocoon is made up of a structure protein with the general properties of the arthropod sild fibroins. 3. 3. The implications of the amino acid composition for the interpretation of the molecular organization of the proteins in the cocoon wall, in terms of the X-ray diffraction diagram they give rise to, are commented upon.

1. 1. From tissues of several vertebrates and invertebrates electrophoretic runs were made and developed for α-glycerophosphate, lactic and malic dehydrogenase activity. 2. 2. For each enzyme, organ and species a more or less specific isozyme pattern was demonstrated. 3. 3. For each species electrophoretic bands appeared which showed more than one enzymatic activity. 4. 4. This multi-enzyme activity is discussed. The conclusion is drawn that the most likely explanation for this composite activity may be that different enzymes are attached to and distributed by series of more or less species-specific carriers. The result of such association will be isozyme patterns with combined activities at certain electrophoretic sites.

1. 1. Acetate-14C incorporation by the homogenates of the eggs, larvae, pupae and adults of Ceratitis capitata shows clear differences. The pupal and larvae stages of development exhibit the most effective incorporation. 2. 2. NADPH influences the acetate incorporation in a different way. It enhances the incorporation by larval homogenate whereas it produces a net decrease of the incorporation by pupa homogenate. 3. 3. Citrate decreases the acetate incorporation by all homogenates. This effect is higher in the pupal homogenate. As for the influence of citrate on the activatory effect of the mixture ATP-Mg2+ in larval and pupal homogenates, incorporation by larval and pupal homogenates is enhanced and decreased respectively. 4. 4. Differences in the regulation of fatty acid synthesis during larval and pupal stages of development are clearly shown.

1. 1. The effect of the environment temperature upon the oxygen consumption of the chick embryo during the latter stages of incubation has been investigated. 2. 2. The embryo was found to be essentially a poikilotherm up to the moment of escaping from the shell membranes. 3. 3. A transient homeothermic response in both the 19-day-old embryo and the parafoetus was demonstrated when cooling was greater than 3°C. 4. 4. The neutral condition in the prafoetus could only be demonstrated when the cooling was less than 3°C. 5. 5. The nature of the primary thermoregulatory response is discussed.

1. 1. Captive redpolls maintained under constant conditions of light and temperature and fed three diets with different fatty acid compositions deposited the same composition of fatty acids in their depots regardless of diet. 2. 2. The depot fat of wild caught redpolls which were feeding on a natural supply of Chenopodium seed during migration contained over 80 per cent linoleic acid, three times as much as the captive birds, and twice as much as wild redpolls in the breeding season. 3. 3. It is suggested that the environmental conditions of photoperiod, temperature and captivity and the physiological state of the bird (migration, breeding, etc.) exert a greater affect on the fatty acid composition of the birds' depot fat than does diet per se .

1. 1. Extraction of catecholamines from Lumbricus terrestris ventral nerve cords followed by thin-layer chromatography of the extracts reveals the presence of dopamine as the predominant catecholamine. 2. 2. Noradrenaline is also present, but in smaller amounts. 3. 3. No adrenaline was detected by these methods. Occasionally DOPA was present.

Photoperiod variation effects on ambulatory primate Cebus albifrons deep body temperature /DBT/, locomotor activity /LMA/ phase relationships and DBT waveform

1. 1. A cardiac output of 18·3 ml/min per kg (SE 1·87) was determined by the Fick principle for resting Cyprinus carpio at 10°C. 2. 2. Gill blood flow seems to be directly related to the total oxygen consumption. 3. 3. It is suggested that the cardiac output decreases when the O2 tension of the ambient water falls below a critical level and increases as the fish becomes anemic. 4. 4. Cardiac work in resting carp requires about five per cent of the energy production.

1. 1. The green pigment in the foot of Monodonta turbinata was isolated. 2. 2. The free pigment was found to be a hydrophilic substance green in acid and yellow in alkaline solution. 3. 3. The absorption spectrum of the pigment in methanolic HCl showed maxima at 680 and 370 mμ (E370/E680=0.87), and inflexions at 440, 330 and 270 mμ. The zinc complex exhibited an absorption maximum at 665–670 mνm, and in inflexion at 615 mμ, after oxidation with iodine. 4. 4. The pigment gave the Gmelin reaction. It did not react with diazotised sulphanilic acid. 5. 5. It is suggested that the pigment is a bilatriene. 6. 6. Green pigment with an identical absorption spectrum was isolated from foot tissue of the realted species Monodonta articulata.

1. 1. Decreased survival occured for juvenile coho salmon following doses of X-radiation ⩾ 1000 r when transferred from hypo-osmotic to a hyperosmotic environment (0%–30% salinity). 2. 2. Survivors which had remained in salt and fresh water 60 days post-irradiation were sacrificed for plasma sodium, chloride and osmotic concentrations. Increased levels (P 0·01) were noted between the control (0 r) and the irradiated (⩾1200 r) group of saltwater fish; while no significant elevations occured between irradiated and non-irradiated fish remaining in fresh water. 3. 3. Sites of histopathological changes in saltwater fish were found principally in the extrarenal system (gills, caecae and intestine) with severe damage noted in the gill lamellae. No damage was apparent in the kidney. 4. 4. No histopathological changes were noted in fish receiving the same anount of irradiation but which remained in fresh water.

1. 1. The amine oxidases of Malpighian tubules of Periplaneta americana L. and Blaberus discoidalis Serville accepted agmatine and short-chain aliphatic diamines as substrates; heptamethylene diamine was the subtrate most rapidly oxidized. 2. 2. The Blaberus enzyme did not act upon any monoamine tested. New substrates of the Periplaneta oxidase included the straight-chain aliphatic monoamines. 3. 3. These reactions were not inhibited by semicarbazide.

1. 1. Fatty acid distribution in neutral and polar lipids from different development stages of Ceratitis capitata shows regularly higher ratios of palmitic and palmitoleic acids in the neutra; lipids while streatic and oleic acids are more abundant in the polar ones. 2. 2. The main isomer is 16:1ω7 and its level is higher in the neutral than in the polar classes. 3. 3. On the other hand, 18:1 fatty acids are present as both 18:1ω9 and 18:1ω, the first one being the more important from a quantitatuve point of view. 4. 4. Nevertheless, the significant amount of 18:1ω7 exhibited by egges and adults allows the suggestion of its participation in some specific role during development.

1. 1. Seventy per cent or more of the acetylcholine and 5-hydroxytryptamine in Mercenaria ganglia is bound to particles which sediment when homogenates of this tissue, prepared in 1·1 M glucose, are centrifuged at high speed. 2. 2. Similarly, a large proportion of the unidentified cardio-excitatory factor, Substance X, is particle bound in Mercenaria ganglia. 3. 3. Particles binding each of these substances have been partially separated from each other by density gradient centrifugation. The acetylcholine particles were mainly associated with the least dense layers of the gradient, 5-hydroxytryptamine with more dense layers and Substance X with layers of intermediate density. 4. 4. A fraction of 5-hydroxytryptamine particles has been purified twenty times over the original homogenate. The level of acetylcholine contamination of this fraction, if any, was below the limit of detection. 5. 5. Particles binding acetylcholine and 5-hydroxytryptamine release their active substances in a quantitatively similar manner to changes in pH, hypotonicity and increased temperature.

1. 1. The enzymes involved in the tricarboxylic acid cycle were investigated in Haemonchus contortus and the results compared with those obtained for the corresponding enzymes in rat liver. 2. 2. Succinic dehydrogenase and the oxoglutarate dehydrogenase system were detected in a particulate preparation from H. contortus, their specific activities being about one-third those of the corresponding enzymes in rat liver. The succinic dehydrogenase of H. contortus resembled that of facultative anaerobes in its relative rates of succinate oxidation and fumarate reduction. 3. 3. The level of citrate synthase activity in H. contortus crude homogenates was much greater than that in rat liver, the bulk of this activity being retained by the supernatant fraction. In rat liver the specific activities of the supernantant and particulate fractions were almost equal. 4. 4. The level of NADP specific isocitrate dehydrogenase in H. contortus was about one-sixth that in rat liver, although the intracellular distribution of this enzyme was similar in both tissues, the supernatant containing most of the activity. 5. 5. In contrast to the exclusive localization of NAD specific isocitrate dehydrogenase in the mitochondrial fraction of rat liver homogenates, considerable activity was detected in the supernatant fraction of H. contortus homogenates as well as in the particulate fraction. Like that of vertebrate tissue, the NAD specific isocitrate dehydrogenase of H. contortus was activated by ADP. 6. 6. Aconitate hydratase, fumarate hydratase and malate dehydrogenase were present in H. contortus and their intracellular distribution and specific activities were very similar to those of the corresponding rat liver enzymes. 7. 7. The particulate fraction from H. contortus was found to be a poor source of some of the enzymes of the tricarboxylic acid cycle, especially of aconitate hydratase and NADP specific isocitrate dehydrogenase, much higher levels of activity being retained by the supernatant. Similar results were obtained with rat liver homogenates and the implications of these findings in relation to previous reports on the existence of this cycle in other parasites is discussed. 8. 8. It appears that a full tricarboxylic acid cycle can operate in H. contortus under aerobic conditions and the possible role of these enzymes under anaerobic conditions is discussed.

1. 1. The water, sodium, potassium, calcium, magnesium, phosphorus, iron and copper contents of the proboscis, body wall, digestive tract, coelomic fluid and entire specimens of the echiuran worm Lissomyema exilli were determined. 2. 2. Figures for total iodine, nitrogen, total sulphur and chloride were found for the proboscis, body wall and digestive tract. Values for “glycogens” were also obtained for the proboscis and body wall. 3. 3. In the study of the coelomic fluid, determinations of sodium, potassium, calcium, magnesium, phosphorus, copper, chloride, total sulphur, total iodine, protein-bound iodine, protein, albumin, globulin, hemoglobin, cholesterol, uric acid, urea, alkaline phosphatase activity, acid phosphatase activity and osmolality were made. A remarkable value of 934 mg/100 ml for glucose was found in the coelomic fluid. 4. 4. The constitution of the faeces, male and female nephridial contents, and of the muddy sand from collecting places, concerning the diverse elements, is given.

1. 1. Hemoglobins from the American (Anguilla rostrata) and European (Anguilla anguilla) eels were compared electrophoretically. 2. 2. In continous and discontinous starch-gel systems, hemoglobins from both species produced identical patterns. 3. 3. A single variant pattern was observed in the electrophoretic pattern of the American species.

1. 1. The pond turtle ( Pseudemys scripta elegans ) is able to survive for prolonged periods utilizing anaerobic glycolysis as the sole energy source, with approximately constant blood pyruvate concentrations and increasing blood lactate concentrations. 2. 2. The turtle possesses lactate dehydrogenase tetramers with apparently similar M and H subunit polypeptides. 3. 3. This enzyme may represent an important mechanism permitting survival under anaerobic conditions.

1. 1. A membrane preparation from crayfish brain and nerve cord underwent superprecipitation on the addition of ATP. 2. 2. The degree of superprecipitation was dependent on such factors as the concentration of ATP, presence of Mg2+, total ionic concentration and the pH of the reaction medium. 3. 3. Superprecipitation has a characteristic biphasic time-course, in contrast with the linear time-course of the ATPase enzyme activity of the preparation. 4. 4. The glycoside-sensitive and -insensitive fractions of the ATPase enzyme activity of the membrane preparations have differing energies of activation. 5. 5. It is concluded that the ATPase enzyme fractions of the membrane preparation are actomyosin-like proteins. Their possible role in permeability is discussed.

1. 1. The cellular localization of 5-hydroxytryptamine and primary monoamines in the ventral nerve cord of Hirudo medicinalis and Lumbricus terrestris is described. 2. 2. The ganglia of Hirudo medicinalis only contain 5-hydroxytryptamine. 3. 3. This is confined to the soma of six cells, two of which are the giant cells of Retzius. 4. 4. The ventral nerve cord of Lumbricus terrestris contains both 5-hdyroxytryptamine (or 5-hydroxytryptophan) and a primary catecholamine. 5. 5. Many cells show the 5-hdyroxytryptamine fluorescence and are scattered throughout the nerve cord. Only a few cells contain primary catecholamine.

1. 1. One of the pair of pericardial organs (PO's) of Libinia emarginata was removed to a chamber and arranged for simultaneous electrical stimulation and recording. Fluid bathing the PO was assayed for excitatory effect on the isolated, perfused crab heart. 2. 2. A low level of spontaneous release of excitatory material and spontaneous electrical activity, interpreted as action potentials in one or a few axons, were observed in many PO's. 3. 3. A high rate of release of active material was observed only when stimulation resulted in a compound action potential showing a large component representing fibers of 1 4 to 1 2 m/sec conduction velocity. 4. 4. This electrical component and release of excitatory material showed the same threshold and optimal values of stimulus voltage, and the same maximum, 10/sec, for response to repetitive stimulation. 5. 5. The excitatory effect of the fluid was proportional to the number of stimuli given. 6. 6. It is concluded that action potentials propagated in axons of neurosecretory cells result in release of neurosecretory material from the terminals.

1. 1. When the nasal sac of spawning salmon is irrigated with water from the spawning site a high amplitude electroencephalographic response of characteristic pattern may be recorded from the olfactory bulb. 2. 2. This electrical response is specific in the sense that it cannot be evoked by water from spawning sites of other groups of breeding salmon. 3. 3. Weaker, but clear responses could be evoked by waters (a) traversed by the fish migrating toward the spawning site, (b) from the by-passed branch of a stream near the spawning site and (c) from a point upstream of the spawning site.

1. 1. Tilapia mossambica responds to starvation by a partial depletion of liver glycogen and by resorption of liver tissue. 2. 2. Short-term injections of ACTH serve to block, in part, the resorption of liver tissue but do not affect the rate of glycogen turnover nor the synthesis of liver glycogen following an intraperitoneal injection of glucose. 3. 3. Chronic injections of ACTH block both the resorption of liver tissue and a net synthesis of liver glycogen following the injection of glucose. Such treatment does, however, markedly stimulate glycogen turnover.

1. 1. A study has been made of trehalose and other carbohydrates in Artemia salina embryos of two types: one which enters dormancy as a blastula and one which undergoes direct development. 2. 2. After 10 hr of development the presumptive dormant embryo contains at least eight times and amount of trehalose present in the non-dormant embryo. When the blastula enters dormanyc trehalose constitutes about 15 per cent of the dry weight, whereas non-dormant embryos of comparable age have essentially no trehalose. 3. 3. Analyses of female hemolymph and studies on presumptive dormant embryos in vitro show that trehalose is snythesized by the developing embryos. 4. 4. The glycogen levels of both types of embryos are similar after 10 hr of development. During subsequent development of the presumptive dormant embryo the glycogen content decreases markedly, but it remains at a high level in the non-dormant embryo. 5. 5. Presumptive dormant embryos contain about twice the amount of glycerol present in non-dormant embryos after 10 hr of development, and this relationship remains about the same with further development. 6. 6. The significance of trehalose accumulation in Artemia embryos is discussed.

1. 1. Some characteristics of the carboxymethylcellulase component of cellulase from the hepatopancreas of O. gammarella were determined by a viscometric method. 2. 2. Carboxymethylcellulase activity was found to have an optimum pH of 6·5 and optimum temperature of 55°C. 3. 3. Carboxymethylcellulase originated from animal as well as bacterial sources.

1. 1. Clamworms, Nereis virens Sars, respond to chemical stimulation in a quantitative manner while housed in glass tubes. 2. 2. Acceptance and rejection responses were distinguishable and were found to occur, as a function of concentration, upon stimulation with Mytilus extract, amino acids and alcohols. 3. 3. Median rejection concentrations and concentrations at maximal acceptance were determined for a series of nine saturated monohydric alcohols.