bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Temperature and Humidity upon the Survival of Certain Unfed Rat Fleas
Authors: Leeson H. S. 
Published: June 2009

Previous work on the effect of temperature and humidity upon the survival of unfed fleas is criticised in respect of experimental technique. In the present investigation measures have been taken to eliminate as many variables as possible and the methods employed to this end are described.In the experiments, 2027Xenopsylla cheopis, 999X. astiaand 646Ceratophyllus fasciatuswere employed, all unfed and less than 24 hours old at the commencement of the different experiments. Records were kept individually so that a statistical measure of consistency could be made.The following conclusions have been reached:(1) Duration of life of unfed fleas is not influenced by sex.(2) High temperatures and low humidities tend to shorten life; conversely, low temperatures and high humidities, with a possible optimum of about 90 per cent., tend to produce longer lives.(3) Humidity is at its maximum efficiency in this respect at about 18° C.(4) At 37° C. humidity ceases to have any effect upon the duration of life of unfed fleas, and the evidence suggests that there is also a low temperature at which humidity has no influence upon survival.(5) There is no direct proportion between survival of unfed fleas and saturation deficiency of the atmosphere at any temperature.Comparing the species, it was found that:(1)Ceratophyllus fasciatuswas the longest lived, at similar atmospheric conditions.(2)Xenopsylla astialived longer thanX. cheopisat all humidities at 23° C.
The Relation of AdultRhodnius prolixus(Reduviidae, Rhynchota) to Atmospheric Humidity
Authors: Buxton P. A. 
Published: June 2009

1. The paper describes an experimental study on the effect of atmospheric humidity uponRhadnius. The work was carried out on fasting males of known age, kept at 23° C. at different relative humidities; the proportion of water was determined after the lapse of definite periods of time. The normal male contains 30 per cent. of dry matter.2. Taking the results after 42 days' starvation, at 30, 60 and 90 per cent. humidity, the weight of each group of bugs has fallen to 50 per cent. of what it was at the start of the experiment. Those kept in damp air have lost dry matter and water in the same proportion, so that the percentage of dry matter after starvation is still 30 per cent. of the total weight. Those kept in drier air lose more water but oxidise less dry material, so that the proportion of solids rises during starvation: in those kept at 30 per cent. relative humidity the proportion of solids rises to 39 per cent. The figures for insects kept at 0 per cent. humidity are consistent, but it is not possible to obtain them beyond the 32nd day.3. Death is probably due to a rise in the concentration of the body fluid and not to the exhaustion of food material. This is shown by the fact that the exhaustion of solid matter is actually less in dry air than in moist, though mortality is only observed among the bugs kept in dry air.
Note on a Schistosoma Cercaria with Four Pairs of Flame Cells in the Body
Authors: Archibald R. G. , Marshall A. 
Published: June 2009

1. A brief account is given of a schistosoma cercaria obtained from Bulinus truncatus possessing four pairs of flame cells in the body.A monkey, Cercopithecus sebaeus, was experimentally infected with this cercaria, adult male and female S. haematobium being formed in the mesenteric veins, and terminal spined ova in the sub-mucosa of the colon.The view is expressed that this cercaria was probably an aberrant form of the cercaria of S. haematobium.
Structure, hatching and size variation of the spores in a species of Nosema (Microsporidia) found in Hyalophora cecropia (Lepidoptera)
Authors: Walters V. Ann 
Published: June 2009

1. A brief outline of the life cycle of a species of Nosema parasitic in Saturniid moths is given. It is of the normal type.2. The structure of the spore is described, and from electron microscopy evidence is presented which supports the theory that the sporoplasm is injected into the host's tissue.3. The volume of the spore is affected by the ambient medium, by the pretreatments of fixation and of desiccation, by the site of development within the host and by the age of the host.4. These results have been discussed with reference to the use of spore size as a diagnostic character in the classification of the Microsporidia. It is concluded that spore size is not a reliable character for taxonomic purposes.
An analysis of the development of resistance to metachloridine in clones of Plasmodium gallinaceum
Authors: Bishop Ann 
Published: June 2009

1. The development of resistance to metachloridine (3-metanilamido-5-chloropyrimidine) was studied in two clones of Plasmodium gallinaceum derived from single erythrocytic parasites and maintained by serial inoculation in young chicks. Resistance developed with equal facility and similarly in the two clones.2. In thirteen strains of these clones an enhancement of resistance was obtained after three to five courses of treatment, each of seven doses of metachloridine over a period of 3½ days.3. The effect of the size of the inoculum (2·5 × 107–109 parasites), and of the dose of drug upon the rate of development of resistance was studied. Although the number of courses of treatment required to produce an enhancement of resistance was not always related to the size of the inoculum, with the largest inoculum an enhancement of resistance was observed after the minimum number of courses of treatment (three), whereas with the smallest inoculum no enhancement of resistance was obtained. The rate of the development of resistance did not appear to be related to the size of the dose of drug.4. In some strains the increase in resistance was sudden, whereas in others it was more gradual. Resistance was retained when parasites of a newly resistant strain were transmitted through Aëdes aegypti or maintained for 43 days in the absence of the drug.5. A comparison of the development of resistance in populations of normal parasites, and of populations composed of mixtures of known numbers of resistant and normal parasites, indicated that the pattern of the development of resistance in normal populations could be explained by the selections of mutations of a frequency of less than 1 in 5 × 107, or probably less than 1 in 109 parasites.
On the morphology of the male, female and fourth-stage larva (female) of Hammerschmidtiella diesingi (Hammerschmidt), a nematode parasitic in cockroaches
Authors: Lee D. L. 
Published: June 2009

The male, female and fourth-stage larva (female) of Hammerschmidtiella diesingi are described. Characters are given by which this species can be identified from the female fourth-stage larva.A constriction and ring of clear cells separate the intestine of the male and of the female fourth-stage larva into two parts, and descriptions of the structure and mode of action of this ‘sphincter’ are given.This work was carried out during the tenure of a Research Studentship awarded by the Department of Scientific and Industrial Research.
Revision of the genus Hyalomma II. The subgenus Hyalommina
Authors: Feldman-Muhsam B. 
Published: June 2009

The validity of the subgenus Hyalommina is discussed and reaffirmed.Hyalommina is differentiated from Hyalomma by the absence of the subanal plates in the males and by the humped tarsi and the more or less hexagonal basis capituli in both sexes.The male and the female of H. rhipicephaloides Neumann, 1901 are re-described. The larva and nymph of H. rhipicepholoides are described for the first time.The Indian species H. hussaini Sharif, 1928 and H. kumari Sharif, 1928 are re-described. H. hussaini var. brevipunctata Sharif, 1928 is considered as a species inquirenda.H. lewisi Schulze, 1936 is synonymized with Hyalomma truncatum K., 1844 (Feldman-Muhsam, 1954).
The structure of the cuticle ofAscaris lumbricoidesvar.suis
Authors: Bird Alan F. , Deutsch Karl 
Published: June 2009

1. Nine layers have been identified in the cuticle ofAscaris lumbricoidesvar.suisunder the light microscope and their nomenclature is identical with that of van Bömmel.2. The inner cortical layer consists of a distinct structure which is seen to be markedly different from the homogeneous layer when fresh frozen sections are examined under phase contrast.3. Examination of the outer surface of the cortical layer under the electron microscope after layer stripping and sectioning has revealed the presence of a ridged osmiophilic layer which is less than a thousand Ångström units thick.4. Longitudinal osmium-fixed sections, when examined under the electron microscope, have shown that the external cortical layer has radial striations which appear to link up with the striations which radiate from an aster-like process at the top of the structure arising from the ‘fibrillar layer’.5. The osmium-fixed homogeneous layer, when viewed under the electron microscope, is seen to consist of fine radial striations.6. The fibre layers do not show any finer structures when they are examined under the electron microscope. In longitudinal section, they are seen to consist of irregularly shaped fibres without an internal fibrillar structure. Layer stripping shows that they lack the type of periodic structure seen in collagen.7. The basal lamella is similar, in that the electron microscope does not reveal any finer structures.
The morphology and life cycle of Nosema helminthorum Moniez, 1887
Authors: Dissanaike A. S. 
Published: June 2009

The life cycle of Nosema helminthorum proceeds as follows (see Fig. 39).Emergence of the sporoplasm. The spores swallowed by the vertebrate host (sheep) reach the small intestine where the tapeworm (Moniezia) is already present. Here are extruded the filaments with the sporoplasms attached to their tips. These sporoplasms come in contact with the cuticle of the tapeworm at various places, round off and work their way through the cuticle into the tissues of the worm.Schizogony. They next proceed between the subcuticular cells (3) and start multiplying by binary fission or by multiple division (4, 5, 6, 7). Some of the so-called schizonts are spherical with three to four nuclei (6), while others are elongate plasmodia which give rise to chains of daughter-schizonts by division (7). All these schizonts give rise eventually to faintly staining schizonts in which the nuclei appear to be less compact. Some of these now enter the second phase of schizogony in which elongate fusiform or spindle-shaped cells are ultimately produced (10, 14). The nuclei of these elongate cells divide and move to the opposite poles, and the cytoplasm constricts between them. In this way a chain of fusiform schizonts may be formed (11). The final products of these divisions are fusiform or spindle-shaped cells (11, 15) which are really the precursors of sporonts, in which the nuclei are divided but not separated. These nuclei remain closely associated and eventually fuse either before the sporont stage is reached or later.Sporogony. The sporonts are ovoidal cells which are generally uninucleate after fusion of the double nuclei of the previous stage. The nucleus is at the centre. Soon a vacuole is formed at the posterior pole, and within it there appears a premetachromatic granule (16) which gives rise to the metachromatic body in the mature spore.Spore formation. A chitinous spore wall is then secreted (17) and the filament is probably formed at this stage in the central axis of the cytoplasm. The rest of the cytoplasm transforms into the sporoplasm, which surrounds the filament like a girdle (18). The spore now becomes mature and is infective to a new host. It is passed out within the gravid segments of the worm and, when it reaches the exterior, is liberated when the segments degenerate. These spores are quite resistant and probably remain dormant during the winter; they are swallowed by Moniezia-infected lambs in spring, when the cycle is resumed.It is unlikely that the oribatid mite, which is the vector of Moniezia, plays any role in the transmission of Nosema helminthorum. My experimental studies (to be published later) suggest that the only possible part played by the mite is to carry the spores, accidentally swallowed by it, protecting them till they reach the adult worm already present in the intestine of the vertebrate host.
A new species of Neoascaris from Rattus assimilis, with a redefinition of the genus
Authors: Sprent J. F. A. 
Published: June 2009

Neoascaris mackerrasae from the small intestine of the Australian allied rat (Rattus assimilis) is described. It is compared with Neoascaris vitulorum and found to differ as follows:(1) It is a considerably smaller species.(2) The vulva is situated more posteriorly.(3) The nucleus of the dorsal oesophageal gland is oval and situated in the dorsal sector of the ventriculus, whereas in N. vitulorum it is elongate and is situated in the sub ventral sectors.(4) The eggs are more coarsely pitted.(5) The spicules have two flanges which form a gutter on the ventral surface, whereas in N. vitulorum they are almost cylindrical.The genus Neoascaris is redefined so as to include the presence of rudimentary cervical alae and the unequal distribution of the oesophageal glands. The genus is placed in the family Toxocaridae Hartwich, 1954.Other ascaridoid parasites occurring in rodents are listed and differentiated from N. mackerrasae. It is suggested that on account of the arrangement in the ventriculus of the nuclei of the oesophageal glands, N. mackerrasae may represent a primitive species among the ascaridoid parasites of mammals.
The ingestion of particulate fat from the blood by Trypanosoma lewisi and Trypanosoma equiperdum
Authors: Wotton R. M. , Halsey H. R. 
Published: June 2009

The ability of certain species of trypanosomes (T. lewisi and T. equiperdum) to ingest previously stained oil drops which occurred simultaneously in the blood has been observed.Tryparsamide incorporated in dyed (Sudan IV) cod-liver oil.when administered orally, was found to be effective against T. equiperdum infections in mice.
Morphology and Life-cycle of an Amoeba Producing Amoebiasis in Reptiles
Authors: Geiman Quentin M. , Ratcliffe Herbert L. 
Published: June 2009

The morphology and life cycle of an amoeba producing amoebiasis in reptiles is described. The organism is assigned to the species Entamoeba invadens Rodham 1934, because of the pathogenicity of that species.Material for the study was derived from 30 individuals of 7 species of reptiles, either dying of spontaneous amoebiasis or experimentally infected. (Material from 3 additional species of reptiles dying of amoebiasis was not used in this study.)With the exception of a few minor morphological differences, E. invadens was found to be strikingly similar to E. histolytica in morphology of trophic and cystic stages, and in the processes of encystation, excystation, and metacystic development.Metacystic development was studied in stained preparations made from the intestines of snakes 1–24 hours after the inoculation by mouth of mature cysts. Excystation usually takes place in the jejunum and ileum, a single quadrinucleate amoeba hatching from each cyst. Each quadrinucleate metacystic amoeba ultimately forms 8 amoebulae as a result of one division of each cystic nucleus, cytoplasmic division, and parcelling out of the cystic (N) and daughter (n) nuclei. Nineteen of the 24 possible combinations of N and n nuclei were observed.The culture phenomena of multiple fission without encystment is suggested, and cannibalism of cysts by the trophozoites is described.
Notes on New Aspidogastrid Species, with a Consideration of the Phylogeny of the Group
Authors: Faust Ernest Carroll , Tang Chung-Chang 
Published: June 2009

1. Cotylaspis sinensis and Lophotaspis orientalis are described as new species of trematodes from the small intestine of the turtle, Amyda tuberculata, from Foochow, Fukien Province, China.2. Stichocotyle cristata is described as a new species from the spiral valve of the cow-nosed ray, Rhinoptera quadriloba, from Biloxi Bay, Mississippi.3. A new subgenus, Multicalyx, is created for the species Stichocotyle cristata, while the species S. nephropis appropriately belongs to a new subgenus Stichocotyle.4. Evidence is provided that aspidogastrid worms are referable neither to the Monogenea nor the Digenea, but belong to an intermediate subclass group, Aspidogastrea, n.n.5. The genus Stichocotyle has been removed from the family Aspidogastridae Poche, 1907, and placed in a new family, Stichocotylidae.
The Significance of thepH in the Development of Mosquito Larvae
Authors: MacGregor Malcolm E. 
Published: June 2009

1. Previous work by the writer drew attention to the fact that thepH index of natural waters was in some manner correlated with the presence or absence of particular mosquito larvae.2. The observation led other investigators to study this hypothesis, and a short summary of their published records is given.3. The actual significance of thepH index was, however, obscure, and the present work has been undertaken to attempt to demonstrate the actual significance of thepH in mosquito breeding-places.4. By gradually eliminating first one and then another of the interacting factors, the writer has been able to demonstrate (a) that if thepH of the normal environment is changed the development of the larvae is adversely affected; (b) that under bacteriologically sterile conditions the foregoing statement is no longer true; and (c) that consequently the acid or alkaline reaction of the medium, within ordinary limits, has no direct effect upon the development of the larvae.5. Nevertheless, it is shown that the influence of thepH. is of unquestionable importance and that its significance lies in the fact that, under natural conditions, it indicates the favourable or unfavourable association of chemical and biological factors in the breeding-places upon which the successful or unsuccessful development of the larvae depends.6. It may therefore be stated that although thepH index is not an infallible guide, it does in the majority of instances provide a reliable index as to whether the necessary combination of chemical and biological factors in any given water are such that they will permit the development of the larvae of particular species. Some species find their optimum conditions for development in waters which are acid, others in waters which are alkaline, and it can be shown that to alter thepH of such waters is often to bring about a complete change in the biological group associations, which frequently means the acquired abnormal dominance of factors unfavourable to a particular species of larvae. Clearly, the system is to some extent elastic, and in rare instances what are in general acidophile larvae may be found in waters showing alkalinity.7. The chief conclusion is, however, that in most instances in various localities the larvae of certain species do actually show a restriction to waters exhibiting apH index within a definite short range, and that thepH index is consequently often a reliable index also as to whether the chemical and biological group associations will favour or preclude the successful development of such larvae.8. A new technique is described for the production of a high percentage of successful cultures ofAëdes argenteuslarvae and pupae under bacteriologically sterile conditions.9. The phase of “suspended development” has been investigated and is found to have its probable explanation in the temporary or complete disappearance of micro-organisms on which the conversion of the organic materials of the environment, to a suitable larval diet, depends.
The Susceptibility of Autogenous and Anautogenous Races of Culex pipiens to Infection with Avian Malaria (Plasmodium relictum)
Authors: Tate P. , Vincent M. 
Published: June 2009

1. Anautogenous English and autogenous Greek, Hungarian, Maltese and cross-bred strains of C. pipiens were infected with an Algerian and a German strain of P. relictum.2. The different strains of C. pipiens behaved similarly as regards susceptibility and transmission towards the same strain of P. relictum.3. The two strains of malaria differ in the infection rate produced in mosquitoes. The Algerian strain produces an infection rate of about 89 per cent., while that of the German strain is only about 43 per cent.4. The difference in the infection rates of the two strains is not due merely to differences in the number of gametocytes formed.5. In general C. pipiens fed on birds infected with the Algerian strain of malaria became more heavily infected than those fed on birds infected with the German strain.6. C. pipiens were infected in some cases by feeding on birds with chronic infections of the Algerian strain of P. relictum, but not when fed on birds with chronic infections of the German strain.7. No seasonal influence was found as regards the infection of C. pipiens by P. relictum.8. The Algerian strain of malaria was successfully transmitted by English, Greek, Hungarian, Maltese and Greek-Hungarian strains of C. pipiens, and the German strain of malaria by English, Greek, Maltese and Greek-English strains of C. pipiens.
The Action of Atebrin on Bird Malaria
Authors: Tate P. , Vincent M. 
Published: June 2009

1. Atebrin given during the incubation period delays the appearance of parasites in the blood of birds infected by direct blood inoculation with Plasmodium relictum.2. If given to birds infected by the bites of mosquitoes it does not retard the appearance of parasites in the blood, when given either before, or after, the infective bites, but it has some action in diminishing the severity of the attack and the degree of splenic enlargement.3. Parasites appear in the blood of birds, infected by sporozoites, actually during the course of atebrin treatment if this is prolonged beyond the normal incubation period.4. When asexual parasites appear in the blood of mosquito-infected birds after atebrin treatment they are abnormal in appearance and devoid of pigment grains; gametocytes are rarely seen in the blood of such birds, but if present they have normal pigment granules.5. Treatment with atebrin produces peculiar bodies in the blood cells of canaries.
Certain aspects of the host-parasite relationship of Nematospiroides dubius (Baylis): IV. The effect of the host's age on experimental infections in the mouse and rat
Authors: Dobson Colin 
Published: June 2009

1. The mouse and rat (an abnormal host) show an age resistance towards experimental infections with N. dubius.2. This resistance was complicated by a different reaction in the male and female mouse and rat.3. The rat exhibits age resistance despite being gonadectomized immediately after weaning.4. Gonadectomy with replacement of the homologous sex hormone did not materially alter the age resistance of the host, but the administration of testosterone to the castrated male rat increased the numbers of larvae which penetrated the gut wall. Oestradiol decreased these numbers in the spayed female rat.5. The relationships between the age resistance and the sex resistance of the hosts was discussed.
The development of Spirochaeta duttoni and S. recurrentis in Pediculus humanus
Authors: Heisch R. B. , Harvey A. E. C. 
Published: June 2009

1. The development of S. duttoni and S. recurrentis was studied in lice.2. After penetrating the anterior part of the midgut spirochaetes were seen in the haemocoele, haemocytes, neural ganglia and muscles of lice. They were never seen elsewhere.3. The haemocytes of infected lice sometimes contained coarse granules believed to be the breakdown products of spirochaetes due to phagocytosis.