bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Larval Development ofDacnusa areolarisNees (Braconidae), a Parasite of Phytomyzinae (Diptera), with a Note on certain Chalcid Parasites on Phytomyzids
Authors: Haviland Maud D. 
Published: June 2009

1.Dacnusa areolarisNees is a parasite of the flyPhytomyza angelicaeZett.2. The egg is laid and development takes place within the body of the host.3. A membrane of trophic cells is formed, within which the embryonic and first larval stages are passed.4. The further growth and development of the parasite are delayed until after metamorphosis of the host, probably to ensure sufficient food in the later stages.5. The length of the larval and pupal life of the parasite is intimately correlated with the puparial period of the host.6. It is suggested that this is an adaptation to ensure that an adequate supply of host larvae shall be hatched by the time that the parasites are ready to oviposit.7. Certain Chalcididae of the generaEulophusandChrysocharisare ectoparasites ofPh. angelicae, and a summary of observations on their life cycle is given.
Studies on some Sporozoa in Polychaete Worms
Authors: Ray Harendra Nath 
Published: June 2009

1. The main facts in Brasil's (1907) account of the intracellular schizogony inSelenidium caulleryifromProtula tubulariahave been confirmed. Early stages in the sporogony of this species are described now for the first time.2. Intracellular schizogony is described for the first time inSelenidium mesniliBrasil fromMyxicola infundibulum, and here also the early stages in sporogony are noted for the first time.3. The life histories of Caullery and Mesnil's two unnamed species ofSelenidium(now calledS. spionis(Köll.) andS. foliatumn.sp.) fromScolelepis fuliginosahave been exhaustively studied. No schizogonic phase has been observed in either. The gametocysts, here described for the first time, are found to develop fully only after escape into the sea. The gametocysts ofS. spionisare ovoid, 108μ x 60μ and contain spores with four sporozoites: those ofS. foliatumare spherical, 70μ in diameter, and their spores contain eight sporozoites.4. New or hitherto little known species ofSelenidiumare recorded fromCirratulus cirratusMüll.,Branchiomma vesiculosumMont.,Sabella pavoninaSav.,Pomatoceros triqueterL. andTerebella lepidoriaKühl, and the morphological characters of the trophozoites are described.5. A discussion follows of the value of the diagnostic characters of the genusSelenidium. It is suggested that this genus requires drastic revision and will probably have to be dismembered. Stress is laid, however, on the occurrence in all the gregarines examined, and at all the observed stages of their development, of characteristic chromatic bodies at the anterior end, structures which have hitherto escaped the notice of most observers.
Direct and indirect actions of radiation on viruses and enzymes
Authors: Lea Douglas , Smith Kenneth M. , Holmes Barbara , Markham Roy 
Published: June 2009

1. The inactivation by γ-rays of tobacco mosaic virus is studied at various concentrations. It is found that the inactivation dose is independent of concentration at high concentrations, and at low concentrations also attains a constant, but lower, value. Over an intermediate range the inactivation dose increases with increase of concentration.2. These facts are explained on the basis that when irradiated dry or in concentrated solution the inactivation is direct and due to ionization produced inside the virus particle. At lower concentrations the inactivation is largely indirect and due to ionization of the water.3. Gelatin added to the solution protects the virus against the indirect action of radiation.4. Curves are given of the inactivation of dry preparations of ribonuclease and adenylpyro-phosphatase (myosin) by X-rays.5. It is shown that on the assumption that a single ionization in an enzyme molecule leads to its inactivation, measurement of the inactivation dose leads to a rough estimate of the molecular weight of the enzyme.6. There appears to be no fundamental difference in the mechanism of radiation-inactivation of viruses and enzymes.All irradiations were carried out at the Strangeways Laboratory. The virus was prepared and tested at the Plant Virus Station and the Molteno Institute. The enzymes were prepared and estimated at the Biochemical Laboratory. We are indebted to the British Empire Cancer Campaign for defraying the cost of the X-ray equipment at the Strangeways Laboratory.
The Culicidae of the Cambridge District
Authors: Macan T. T. 
Published: June 2009

1. The mosquito fauna of the Cambridge district, which includes a large stretch of cultivated fenland, is compared with that of the “natural” fen at Wicken and also with that of other districts.2. The ecology of the various species is discussed and the conclusion is reached that the main factor determining why different species are found in different types of habitat is the time of year at which the female lays her eggs, and whether she lays them on damp ground or standing water.
The transmission of plant viruses by aphides
Authors: Smith Kenneth M. , Lea D. E. 
Published: June 2009

1. Experiments are described on the transmission of mottle and vein-distorting viruses by aphides.2. A quantitative analysis is made of Watson's experiments on the aphis transmission of persistent and non-persistent viruses. The principal features of the experimental results can be explained in terms of different rates of inactivation of the virus in the insect.3. It is shown that these considerations explain why non-persistent viruses are more commonly sap-transmissible than persistent viruses.
Descriptions of Three New Species of Tetrophthalmus (Mallophaga) found on Pelicans
Authors: Bedford G. A. H. 
Published: June 2009

On comparing the figures it will be observed that all the specific characters of Tetrophthalmus titan (A in all figures) closely resemble those of T. subtitan (B in all figures), and that these two species constitute one group; also that the specific characters of T. africanus (C in all figures) closely resemble those of T. australis (D in all figures), and that these species belong to another group, which must also include T. chilensis.Judged by their parasites, the Ethiopian pelican, Neopelecanus rufescens, is more closely allied to both the Australian pelican, Catoptropelecanus conspicilatus, and the South American species, Pelecanus thagus, than it is to either Pelecanus onocrotalus or Metapelecanus roseus, both of which also occur in the Ethiopian region. Moreover, if the parasites throw any light on the phylogeny of their hosts, thagus cannot remain in the genus Pelecanus along with onocrotalus if the genera Neopelecanus, Metapelecanus and Catoptropelecanus are to remain valid.
The Hydrogen Ion Concentration of the Soil and Natural Waters in relation to Diseases other than Bacterial
Authors: Atkins W. R. G. 
Published: June 2009

Certain facts are known concerning the correlation of the distribution of animal species and the hydrogen ion concentration of the soil and water. An attempt is made to apply them to the distribution of malarial fever, as illustrating insect borne disease, and to some of the numerous Trematode infections, afflicting man and other animals, in which snails act as intermediate hosts. The importance of measurements of hydrogen ion concentration (by the colorimetric method) by field workers on the distribution of animals is urged.The writer wishes to acknowledge his indebtedness to Dr M. V. Lebour for the suggestion that snails may prove a suitable group for the study of the relation between the reaction of the habitat and animal distribution.
A Comparison of the Physiology of the Two Species of Bed-bug which Attack Man
Authors: Mellanby Kenneth 
Published: June 2009

The two species of bed-bug,Cimex lectulariusandC. rotundatus, are found in temperate and tropical regions respectively. They are very similar anatomically, and have the same habits.Physiologically, the two species have many resemblances. Their water balance is similar; they are very little affected by humidity if there is plenty of food available. The thermal death-points are identical.At temperatures below 30° C.,C. lectulariusis able to breed more rapidly and more successfully thanC. rotundatus.Between 30 and 35° C. both species behave alike, and above 35° C.C. rotundatusmay be the more efficient species. Under most conditions,C. lectulariusis the more resistant to starvation and desiccation.Results indicate that althoughC. lectulariusis more fitted for life in temperate countries, if introduced into the tropics it should be able to carry on at least as well asC. rotundatus.Studies of geographical distribution indicate thatC. rotundatushas spread all over the tropics, but has never established itself outside them.C. lectulariushas spread all over the temperate world, and into the ports in some tropical countries. Experimental work suggests that it may become widespread in those parts of the tropics into which it is introduced.
Studies on the behaviour of Trypanosoma evansi in tsetse-flies with special reference to its phylogeny
Authors: Hoare Cecil A. 
Published: June 2009

In view of the morphological similarity of T. evansi and T. brucei, including the sporadic occurrence of marked polymorphism in the first-named species, the hypothesis is advanced that T. evansi may have originated from T. brucei, by the introduction of the last-named species into localities free of Glossina and its subsequent propagation by direct passages.The possibility of contact between the mammalian host of T. evansi, on the one hand, and Glossina and tsetse-borne trypanosomiases, on the other, is shown to exist in the Anglo-Egyptian Sudan, thus pointing to the source from which T. evansi in that country may have originated and providing circumstantial evidence in support of the hypothesis.Attempts were made to discover whether T. evansi is capable of developing in Glossina. A total of 568 flies were fed on infected mice and examined at periods from 6 hr. to a fortnight following the infective feed. The results were entirely negative: not only is the trypanosome incapable of establishing an infection in the fly, but the majority of flagellates perish and are digested during the first hours after ingestion by the insect.The behaviour of T. evansi in tsetse is shown to be similar to that of non-transmissible strains of trypanosomes of the Brucei group after prolonged maintenance by direct passages in the mammalian hosts, and is therefore also in keeping with the hypothesis.
The inactivation of plant viruses by radiations
Authors: Lea D. E. , Smith Kenneth M. 
Published: June 2009

Experiments are described on the inactivation by gamma-rays, X-rays, and alpha-rays of the viruses of tomato bushy stunt, tobacco necrosis, tobacco ringspot, tobacco mosaic and potato virusX. Within the errors of the experiment the inactivation curves appear to be exponential, and the inactivation doses increase in the order gamma-rays, X-rays, of wave-length 1·5 A., X-rays of wave-length 8·3 A., and alpha-rays.A theory is given explaining these results and correlating the inactivation dose with the virus size. Estimates of the sizes of the viruses obtained from the radiation experiments he within the range of the sizes given by other methods, but are somewhat lower than the most probable sizes. Possible explanations of the discrepancy which are discussed are (a) the virus particle is not the molecule, in the sense of the smallest infective unit, or (b) certain structural changes in the virus molecule produced by the radiation may still leave it infective. Some of these may perhaps show themselves as mutations.
Note on a ciliate protozoon, probably Glaucoma Pyriformis, parasitic in culicine mosquito larvae
Authors: Muspratt J. 
Published: June 2009

1. Stained specimens of two forms of a ciliate parasite resembling Lambornella stegomyiae Keilin which is probably Glaucoma pyriformis Ehrenberg are discussed. These were collected from the haemocoel of culicine mosquito larvae at Livingstone, Northern Rhodesia. The form previously referred to as type A (Muspratt, 1945) is the fast multiplying form which destroys the larva and that referred to as type B is considered to be either an encysting or degenerate form.2. In nature the larva of Aëdes (Finlaya) fulgens Edw. is the most suitable host of the parasite because the normal (type A) parasitic ciliates are dependent on escaping from the larval host before death by the rupture of the anal papillae. This occurs most frequently in parasitized larvae of the above species.3. The encystment of the organisms on the cuticle of the larvae is discussed with reference to statements by previous workers. Stages in the penetration of the cuticle by the organisms and the formation of cuticular resting cysts have been observed.4. Larvae of A. aegypti used in laboratory experiments proved to be unsuitable as: (a) The anal papillae do not rupture easily. (b) After some time the reproductive power of the ciliates degenerates if they are transmitted from larva to larva of this species only.5. Attempts to destroy anopheline larvae with the parasite were negative although the ciliates entered the haemocoel.6. A suggestion as to the possible life-cycle is appended in the form of a diagram.
The ecology of the sheep tick,Ixodes ricinusL.
Authors: Milne A. 
Published: June 2009

Since it is concerned with filling in certain details of a picture, long since sketched in outline, the new work in this paper permits only a somewhat disjointed summary.From a study ofIxodes ricinusL. in nature, the main new facts emerging are:(I)Unfed adults in a deep vegetation layersuch as presented by rough hill or moorland pasture dominated by bents, heather or bracken. (i) Practically allinactiveunfed ticks are in the underlying mat, and nearly all of these in the upper portion of the mat. This distribution does not change, summer or winter. (ii) When the tick is active its progression is practically confined to the vertical, i.e. between its niche in the mat and the vegetation tips immediately above. Random undirected movements due to certain circumstances may achieve a 0–8 in. (average 2 in.) change of position in the horizontal plane; but there is apparently no ruling urge to move in the horizontal plane. (iii) The unfed tick comes to the vegetation tips to await a host for only a limited time during the 3-month activity season. Commonly this amounts to about five periods of 4–5 days each if no host is forthcoming. Between the periods of activity it returns to the upper mat. If it stayed constantly at the tips its survival time would be much shorter than normal. (iv) From nymphs engorged in spring, adults emerge in autumn but remain inactive for a considerable period. About half of them may perish within the first 100 days after emergence. Survivors become active during the following March–June. Effective life ends when the tick, if still unfed, finally stops coming to the vegetation tips, the only position from which a host can normally be achieved. After emergence, the effective life of the unfed adult deprived of a host is less than one year; and the actual life is not much more than one year at best. Thus adults not finding a host in spring will be ineffective, i.e. die without reproducing before the next activity season.
Observations on the vertical migrations of the third-stage larva of Haemonchus contortus (Rud.) on experimental plots of Lolium perenne S24, in relation to meteorological and micrometeorological factors
Authors: Rees Gwendolen 
Published: June 2009

1. The cycle of vertical migration of the infective larvae of Haemonchus contortus on experimental plots of Lolium perenne S 24, kept out of doors, has been related to meteorological and micrometeorological factors.2. The three main factors concerned with vertical migration are temperature, humidity and light intensity.3. In the majority of cases the greatest number of larvae are on the grass blades in the early morning and in the evening, less being recovered at night and during the middle of the day. The time of the morning maximum becomes progressively earlier passing from winter to summer, and the time of the evening maximum progressively later. The reverse is true in the second half of the year.4. Low and high temperatures accompanied by low humidity inhibit vertical migration on the grass.5. High humidity (continuous precipitation) does not prevent migration, the two daily maxima are apparent, but the numbers climbing are less than in the absence of rain.
The differentiation of the eggs of Haemonchus contortus and Ostertagia species of the sheep and a note on the relative generic egg-laying rates
Authors: Tetley J. H. 
Published: June 2009

1. In a mixed infection in which Haemonchus contortus, Ostertagia circumcincta and O. trifurcata predominated, the lengths were plotted against widths of eggs obtained from faeces.2. Two-dimensional groups approximating to normal frequency distributions, showing little overlap, were observed.3. The statistical ranges of means plus and minus twice the standard deviation for the two groups barely touched. These were, to the nearest micron, 68–84 by 41–51 for Haemonchus contortus and, for the Ostertagia group, 83–103 by 46–52.
Egg sizes and differential egg counts in relation to sheep nematodes
Authors: Cunliffe G. , Crofton H. D. 
Published: June 2009

1. The width and length of eggs of Haemonchus contortus, Cooperia curticei, Trichostrongylus axei, T. vitrinus, Bunostomum trigonocephalum, Chabertia ovina, Oesophagostomum venulosum and Ostertagia spp. were measured.2. Frequency distributions of the linear dimensions of the eggs of each species are given, together with the frequencies calculated on the assumption that the distributions are normal.3. A method of species differentiation based on egg measurements is described, the method being based upon the statistical chances of eggs of different species falling into particular size classes.4. The application of the method and the construction of a classifying scale are described.
New Species of larval mites from India (Acarina: Trombiculidae)
Authors: Sinha T. B. 
Published: June 2009

The specimens described in this paper were collected in Assam by Dr M. L. Roonwal during World War II, and were sent to me for identification by Dr S. L. Hora, Director, Zoological Survey of India.I am grateful to Prof. H. R. Mehra, Professor of Zoology, Allahabad University, for his able guidance, to Dr Hora for sending me the material and to Dr Charles D. Radford for his opinion on the species described in this paper.
The influence of environmental factors on the size of the cysts of Entamoeba invadens Rodhain, 1934
Authors: McConnachie Elspeth W. 
Published: June 2009

In dibacterial cultures of E. invadens the size of the cysts was significantly influenced by different species of concomitant bacteria, and by the composition of the media. These factors appear to influence cyst size as a result of their effect on the growth rate of the amoebae; a higher multiplication rate was associated with a decrease in the size of the cysts.I wish to thank Dr A. Bishop for criticizing the manuscript, and Mr W. McConnachie, jun., for assistance with the statistical methods. The work has been financed by the Medical Research Council.
On the Morphology and Life History of Aproctonema entomophagum Keilin, a Nematode Parasite in the Larvae of Sciara pullula Winn. (Diptera—Nematocera)
Authors: Keilin D. , Robinson V. C. 
Published: June 2009

1. An account is given of Aproctonema entomophagum Keilin 1917, a Nematode parasite of the larvae of a Mycetophilid fly, Sciara pullula Winn., inhabiting decaying wood.2. The life history of this parasite is remarkable in the following respects:(a) The free-living stage is very short.(b) Both sexes are parasitic.(c) The usual host is the larva of the fly, from which the parasite escapes by actively breaking through the skin; but some parasites may be carried through to the imagines, from which they escape largely by the aid of the egg-laying movements provoked by them in the flies.3. Metamorphosis of the Sciara larva is delayed by the parasitism, so that at least two generations of Nematodes may be found in one host.4. All the parasitised imagines so far examined have been females.5. The systematic position of Aproctonema is discussed, the conclusion being that this worm and its near relative, Tetradonema plicans Cobb 1919, represent two closely allied genera of the family Mermithidae, but are not synonymous with Mermis. It is proposed to dispense with the family Tetra-donematidae Cobb.
On the Gregarine, Lankesteria culicis (Ross), in the Mosquito, Aedes (Stegomyia) albopictus Skuse
Authors: Ray Harendranath 
Published: June 2009

My observations on Lankesteria culicis, as it appears in Aedes albopictus in Calcutta, show that the trophozoites are intracellular in the anterior and extracellular in the posterior regions of the mid-gut, with epimerite rudimentary in the former and well developed in the latter condition. Full-grown forms measure 150–200 × 31–41μ. Association is lateral. Sporocysts measure about 10 × 6μ and are broadly spindle-shaped with slightly flattened ends, with a-residual body situated more toward one pole than the other.Septate eugregarines in general, excepting the Stenophoridae Léger and Duboscq, grow extracellularly with the epimerite attached to the host cell. Therefore, judging from the foregoing description, we are no longer justified in retaining Lankesteria culicis among the Haplocyte gregarines (Acephalina) and in the family Diplocystidae Bhatia (1930). The presence of a well-developed epimerite and what I consider to be a rudimentary protomerite, clearly distinguish it from any of the Acephalina. Its place should be among the septate gregarines (Cephalina), and perhaps a new genus may have to be erected to receive it there.
On the Development of the Human Hymenolepis nana (Siebold 1852) in the White Mouse; with remarks on “H. fraterna,” “H. longior” and H. diminuta
Authors: Woodland W. N. F. 
Published: June 2009

1. Out of 57 mice (previously ascertained to have been free from “H. fraterna”) 30 were fed on fresh eggs of Hymenolepis nana, the other 27 serving as controls. Out of the 30 egg-fed mice, only 7 were found to be infected (23·3 per cent.) when examined from thirteen to twenty-six days afterwards. None of the 27 control mice showed infection.2. This low percentage of infection (when compared with the 90 per cent, infection obtained in my previous work when I fed 20 mice on “H. fraterna” eggs) is probably due to one or more of three factors: (a) change of host (Grassi records that he found it very difficult to infect wild rats with “H. fraterna” eggs obtained from tame rats and in this case the animals were of the same or closely allied species); (b) the full-grown adult condition of the mice; (c) the perfect health of the mice, due to having been supplied with vegetable food (Vitamin B) every day, this condition rendering the mice refractory to infection. In my previous work the mice were in poor condition owing to deficiency of Vitamin B.3. The proof that rats and mice can be infected with H. nana eggs from Man, the identity of structure of the two parasites and their eggs and their uniform geographical distribution render it practically certain that H. nana and “H. fraterna” are one and the same species. The fact that up to the present there is practically no evidence that Man can be infected with eggs derived from rats or mice does not militate against this conclusion.4. Mature specimens of H. nana found in tame mice vary enormously in size (as already indicated by Joyeux)—between 7 mm and 80 mm. (measured in balsam) in length. “H. longior” (Baylis, 1922) does not exist as a distinct species.5. I failed to infect two Cercopithecus monkeys fed with a plentiful supply of fresh H. nana eggs (from Man).6. Experiments are described which confirm Joyeux's statement that H. diminuta (of the mouse), unlike H. nana, does not possess a direct one-host life-cycle.