bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Adult and Larval Characteristics of a British “Autogenous” Strain of Culex pipiens L.
Authors: Marshall J. F. , Staley J. 
Published: June 2009

1. A strain of Culex pipiens which is autogenous and stenogamic has been found at Hayling Island, England, and compared with British anautogenous strains.2. Definite characteristics in adults of both sexes and in larvae have been found which separate the autogenous from the anautogenous British strains of C. pipiens.3. The autogenous strain differs from the anautogenous strains in (a) the lighter colour of the thorax of the adults; (b) the greater average number of hairs on the ninth tergite of the adults; (c) the relative shortness of the male palps in comparison with the proboscis; (d) the larger average number of branches in each of the four siphonal tufts of the fourth instar larvae; (e) the lower siphonal index of the fourth instar larvae; and (f) the greater width of the egg relatively to its length.
Notes on the Distribution of the Larvae and Pupae of Simulium spp. in the River Tees and its Tributaries
Authors: Pentelow F. T. K. 
Published: June 2009

1. The distribution of the larvae of Simulium spp. in the River Tees area is discussed.2. The dominant species of(a) the upper Tees are S. monticola and S. variegatum;(b) the lower Tees are S. equinum and S. reptansvar. galeratum;(c) the Skerne is S. ornatum.3. The causes of these differences are unknown, but it is suggested that geological structure, the distribution of water plants and the hardness of the water are important factors.
On the bionomics of Aphidius matricariae Hal., a braconid parasite of Myzus persicae Sulz
Authors: Vevai E. J. 
Published: June 2009

1. Aphidius matricariae Hal. is an internal parasite of Myzus persicae Sulz.; it was also found parasitizing M. circumflexus Buckt. and Aulacorthum solani Kalt. (Myzus pseudosolani Theob.).2. The percentage of aphides successfully parasitized increased with an increased number of strikes per host. A single female can lay up to 350 eggs, and one female successfully parasitized 309 M. persicae.3. The female parasite reaches its maximum activity during the 2nd or 3rd day of oviposition, and this activity has no correlation with light intensity.4. The disappearance of supernumerary larvae due to cannibalism has been observed.5. The species is arrhenotokous. Mating takes place from 2 hr. after emergence. In the progeny of early matings the females preponderated; in later matings the sex ratio was approximately 1:1.6. The parasite appears to fly under the same conditions as those generally favourable for aphides. It is generally disseminated by flight of the adult itself and through localized movements of parasitized apterous aphides.7. The host is unable to reproduce if ‘struck’ in the 3rd instar or earlier.
The seasonal activity of the tick,Ixodes ricinusL., in Wales
Authors: Edwards E. E. , Arthur D. R. 
Published: June 2009

A consideration of the tick-activity data for South Wales reveals that there are usually two peaks of female activity in this region, one occurring in spring, the other in autumn. On an experimental area, divided into eight plots, on the Margam Moors, Glamorgan, significantly varying population levels are present on the different plots, although the peak of activity on all of them is attained around the same period. The seasonal activity of the nymphal and larval forms in South Wales is essentially comparable to that recorded by Milne (1945a) in the north of England. There is reason to believe that in mid-Wales a single summer peak of tick activity exists.The engorgement period of female ticks on cattle varies from 7 to 13 days. The tick shows a distinct preference for the hind region of cattle for feeding purposes. The differences in the mean populations of ticks on different breeds of cattle are not statistically significant, at least, on the six breeds tested in 1944 and 1945. In the case of cattle, tick density and fecundity of the female are not correlated with the physiological condition of the host.In South Wales, the populations of ticks on sheep are significantly lower than those on cattle, even where both hosts are pastured on the same ground for similar periods. The seasonal activity of female ticks on horses follows the same general trend as that noted on cattle.
A further revision in the classification of the family Metastrongylidae Leiper [1909] (Phylum Nematoda)
Authors: Dougherty Ellsworth C. 
Published: June 2009

1. Recent studies by Gerichter have demonstrated that I have erred in referring the skrjabingylin lungworms to the family Trichostrongylidae.2. On the basis of his data and a re-evaluation of my theories of metastrongylid evolution it is suggested that the Skrjabingylinae (except Dictyocaulus) are close to the Filaroidinae and that quite possibly the position of the vulva in the former is the consequence of a secondary shift from opening just anterior to the anus to opening in the mid-region of the body; the ‘trichostrongylid’ configuration of the ovejectoral apparatus would thus be convergent.3. The genus Dictyocaulus is removed from the Skrjabingylinae and left in a subfamily Dictyocaulinae in the family Metastrongylidae, although its trichostrongylid affinities are very suggestive. If trichostrongylid, this genus is considered to exhibit convergence with the metastrongylids and not to represent an evolutionary link between the two families.4. The nature of metastrongylid life cycles is discussed, and the compatibility of known data with the evolutionary scheme proposed for the family is pointed out. It is evident that in metastrongylids symbiotizing marine littoral and pelagic hosts (Pinnipedia and Odontoceti) larval development must rely upon new intermediate host groups if the basic pattern has been retained from ancestors in terrestrial hosts.5. The possible importance of histological studies and of investigations on chromosome number and structure for a further understanding of the evolution of the suborder Strongylina is pointed out.6. A revised scheme for the evolution of the Metastrongylidae is presented as Fig. 1. The family Metastrongylidae now includes six subfamilies: Metastrongylinae, Filaroidinae, Skrjabingylinae, Pseudaliinae, Protostrongylinae, and Dictyocaulinae. The basic premises previously expressed (Dougherty, 1949b) on the evolution of the family are retained in the amended scheme.
Latent infections in avian malaria in relation to the production of drug-resistance
Authors: McConnachie Elspeth W. 
Published: June 2009

1. No resistance to paludrine or to sulphadiazine was obtained after treating latent infections ofPlasmodium gallinaceumin chickens with twice daily doses of 20 mg./20 g. of sulphadiazine over periods of 171, 178 and 190 days.2. No resistance to paludrine was obtained after treating a latent infection ofP. relictumin a canary over a period of 1 year with doses of paludrine increasing from 0·05 mg./20 g. once daily to 1·0 mg./ 20 g. twice daily.3. It is considered that if drug-resistance arises by mutation and selection, then resistance should arise more readily when a large number of rapidly multiplying parasites is treated with a drug than when the population treated is small, with a low reproduction rate, i.e. the failure to obtain resistant strains of malaria by prolonged treatment of latent infections with large amounts of drug, lends support to the theory of the origin of resistant strains of malaria by the selection of resistant mutants.
The reactions ofLucilia sericata(Mg.) to various substances placed on sheep
Authors: Cragg J. B. 
Published: June 2009

1. The reactions, under field conditions, ofLucilia sericata(Mg.) to various substances placed on sheep are described.2. Attempts to produce either attraction or oviposition by placing cystine or cysteine hydrochloride in the living fleece gave negative results.3. Several organic sulphur compounds (see Table 1) of a type which might arise from the breakdown of cystine have been tested. All showed some power of attraction forL. sericata. Ethyl mercaptan and dimethyl disulphide were the most powerful as attractants, but none of these substances was able to induce oviposition.4. Tests with ammonium compounds and carbon dioxide have shown that, at the concentrations used, ammonia acted as an attractant. For oviposition to occur carbon dioxide had to be present.5. Hydrogen sulphide was detected as a constituent of the fleece atmosphere of certain sheep. This substance, whilst having no attractive powers when used alone on sheep, increased the attractiveness of organic sulphur compounds.6. Comparative tests with.ammonium carbonate-indole and ammonium carbonate-ethyl mer-captan mixtures have shown marked variations in the relative powers of these preparations to induce oviposition.7. A distinction is drawn between stimuli which attractL. sericatato sheep and those which induce oviposition. Ammonia and various organic sulphur compounds enhanced attraction, but both ammonia and carbon dioxide were necessary for oviposition. It is suggested that some of these materials may be produced under natural conditions from the break-down of fleece keratin or by the bacterial decomposition of sweat and similar products in the fleece.
An experimental study of East Coast fever in Uganda I. A study of the type of East Coast fever reactions produced when the number of infected ticks is controlled
Authors: Wilson S. G. 
Published: June 2009

Doubt exists as to why, in endemic areas, a varying proportion of calves die of East Coast fever while others survive. A series of experiments was therefore conducted to ascertain if the number of infected Rhipicephalus appendiculatus engorging simultaneously on susceptible calves influenced the course of East Coast fever reactions. The ages of the calves used in the various experiments varied, but other conditions were kept as uniform as possible.When ten calves were grazed in a 1-acre paddock where the number of infected R. appendiculatus was high, eight died of acute East Coast fever.In the second experiment, seventeen calves in all were grazed in the same paddock. These calves were given some protection from infected R. appendiculatus infestation, as two of the calves were immune to East Coast fever and the ears of ten of the susceptible calves were sprayed with tickicidal solutions. Four died from acute East Coast fever and one of subacute East Coast fever complicated with a helminth infection.
The ecology of the immature phases of trichostrongyle parasites V. The estimation of pasture infestation
Authors: Crofton H. D. 
Published: June 2009

1. Methods of sampling pastures for infective larvae are discussed.2. An account is given of the methods of operation and identification of larvae from herbage.3. The distribution of larvae on pastures is discussed in relation to choice of method of sampling and interpretation of results.4. The significance of grazing patterns to distribution of larvae is considered.5. An attempt is made to evaluate the use and limitations of pasture sampling methods.The author is indebted to the Agricultural Research Council for financial assistance in the form of a special research grant.
The Life cycle of two Species of “Selenidium” from the Polychaete Worm Potamilla reniformis
Authors: Mackinnon D. L. , Ray H. N. 
Published: June 2009

1. Two new schizogregarines are described from the gut of the polychaete worm Potamilla reniformis (O.F.M.). One of these is meanwhile retained in the genus Selenidium Giard as S. potamillae n.sp. For the other a new genus, Meroselenidium, is proposed, of which M. keilini is the type species. The life cycle has been followed in both gregarines.2. The schizogony of Meroselenidium is characterised by the formation of cytomeres preliminary to the liberation of merozoites. In Selenidium potamillae the schizogony is more like that in S. mesnili and S. caulleryi, though there is a considerable residual body.3. The gametocytes become attached by their posterior ends. In S. potamillae there is often a multiple association. The gamete nuclei are formed within the nuclear area of the gametocytes. Further development takes place in sea water. Isogametes have been observed in S. potamillae.4.The gametocyst of Meroselenidium keilini is elliptical in outline and measures about 70 × 55μ. It contains some twenty relatively large spores, 27 × 15μ, the walls of which are transversely ridged; the spores are polyzoic. The gametocyst of S. potamillae is of much the same shape, but only about half the size. The sporocysts are very numerous, spherical, smooth-walled, and measure about 8·5μ in diameter. In neither species does the gametocyst contain any residual mass.We take this opportunity of thanking the High Commissioner of India and the Delegacy of King's College for grants-in-aid received by one of us (H. N. R.) during the course of these investigations.
Cytological and histochemical criteria for evaluating development of trematodes and pseudophyllidean cestodesin vivoandin vitro
Authors: Bell E. J. , Smyth J. D. 
Published: June 2009

1. Maturation of the plerocercoid of the pseudophyllidean cestodeDiphyllobothriumsp. and the metacercaria of the strigeid trematodeDiplostomum phoxinifollow a similar pattern, which may be divided into the following phases: (1) cell multiplication; (2) segmentation or body shaping; (3) organogeny; (4) early gametogeny; (5) late gametogeny; (6) egg-shell formation and vitellogenesis; (7) oviposition.2. Cytological or histochemical criteria have been developed by means of which each developmental phase may be recognized. Developmentin vitromay be considered comparable with that occurringin vivoif the same phases are completed with the same incubation time and without the appearance of cytological abnormalities.3. The cell multiplication phase is characterized by high mitotic activity. This activityin vitrocan be evaluated by incubating larvae after 24 hr. culture for a standard time (5 hr.Diphyllobothrium; 4 hr.Diplostomum) in 10−4colchicine and comparing the number of mitoses seen in a defined area of an aceto-orcein squash with those found in tissue maturedin vivofor the same period. Use of this criterion enables the growth-producing properties of a medium to be assessed after 24 hr. culture.4. Phases 2–4 are characterized by the appearance of the tubular genitalia, the rudiments of which are readily recognized in aceto-orcein squashes or whole mount preparations.5. The presence of spermatids and mature spermatozoa (phases 4–5) may be detected in aceto-orcein squashes or in fresh tissue teases. The quantity and activity of spermatozoa also serve as important criteria.6. Recognition of phase 6, egg-shell formation, is carried out by means of diazo reagents which give orange or orange-red reactions with the phenolic egg-shell precursors in the vitellaria, as seen in whole mount preparations. Abnormal egg-shell development is reflected in the failure of vitellaria to give a normal diazo reaction.7. The appearance of eggs which are macroscopically normal constitutes the final maturation phase. Early detection of eggs (especially abnormal ones) is facilitated by the use of the diazo reaction or the catechol test for polyphenol oxidase.8. Embryonation and hatching of eggs to produce morphologically normal infective coracidia or miracidia serve as a final criteria.9. Criteria for the maintenance of the adult condition are also considered.
The oxygen uptake ofTrypanosoma lewisiandTrypanosoma equiperdum, with especial reference to oxygen consumption in the presence of amino-acids
Authors: Thurston June P. 
Published: June 2009

1. Standard conditions are described for preparing suspensions of washedTrypanosoma lewisiandT. equiperdumin modified Ringer–phosphate solution.2. Oxygen consumption was measured with differential manometers, using microflasks containing 2–5 × 107trypanosomes in 0·9 ml. of reaction mixture. Measurements of oxygen uptake were carried out at 37° C.3.T. lewisirespired slowly in the absence of substrate for up to 2 hr. The trypanosomes suffered little damage when stored at 5° C. for 24 hr. without substrate. No oxygen uptake was observed withT. equiperdumin the absence of substrate. The trypanosomes were viable after 24 hr. at 5° C. with glucose or glycerol as substrate, but not in the absence of substrate.4. With glucose as substrate, the rate of oxygen consumption byT. lewisiincreased with the age of infection. This change was more marked with glutamine as substrate.5. With glucosamine as substrate, the oxygen uptake ofT. lewisiwas at a slightly lower rate than with glucose. The rate of oxygen uptake was still lower with Nal-glutamic acid, asparagine, aspartic acid, casein hydrolysate, yeast extract and Difco Bacto-peptone. Thirteen other amino-acids had no effect on the motility of the trypanosomes.6. With glycerol as substrate, the oxygen uptake ofT. equiperdumwas at a slightly lower rate than with glucose. The rate of oxygen uptake was very low with yeast extract, casein hydrolysate and Difco Bacto-peptone. No oxygen uptake or motility was recorded with glutamine, Nal-glutamic acid, glucosamine, asparagine, aspartic acid,dl-alanine, or Na acetate. Thirteen other amino-acids had no effect on the motility of the trypanosomes.7. Ammonia was liberated from glutamine by adult and reproductive phaseT. lewisi.
The gametogenesis of the digenetic trematode Sphaerostoma bramae (Müller) Lühe
Authors: Gresson R. A. R. 
Published: June 2009

The stages of spermatogenesis and the structure of the primary oocyte of Sphaerostoma bramae were studied in material fixed in Bouin and Flemming's fluid and in preparations treated according to the Kolatchev and the Feulgen techniques.Chromosome counts of primary and secondary spermatocytes indicate that the diploid number is twenty-four.The stages of spermatogenesis, in general, conform to the usual pattern of this process in digenetic trematodes. The spermatogonia, spermatocytes and early spermatids are not connected together by central strands, nor by a central disk, as is claimed for some other species. A study of sections stained in haematoxylin and of Feulgen preparations showed that the spermatozoon is composed of an elongate nucleus and a tail. It was not possible, with the methods employed during the present investigation, to determine the fine structure of the tail.The primary ovarian oocytes are in the interphase or in early prophase of the first maturation division. There is evidence that material is extruded from the nucleus to the cytoplasm.The Golgi elements of the male germ-cells are revealed in Kolatchev preparations as short rods and filaments. The Golgi elements of the spermatid are eliminated in the residual cytoplasm. Mitochondria, in the form of granular bodies and short rods, were visible in spermatogonia, spermatocytes and spermatids. Those of the spermatid remain in the residual cytoplasm.Short, rod-like Golgi bodies are present in the primary oocytes. In the young cells they form a compact mass situated close to or in contact with the nuclear membrane. Later, the elements spread out through the cell. Granular and rod-shaped mitochondria are concentrated in a single mass at one pole of the nucleus or in two masses at opposite sides of the nucleus. A few mitochondria are scattered through the cytoplasm.
The ecology of the sheep tick, Ixodes ricinus L. Distribution of the tick in relation to geology, soil and vegetation in northern England
Authors: Milne A. 
Published: June 2009

The present findings apply to a particular area, the four northern counties of England, and must be viewed within the limits of the data presented.Only one tick, Ixodes ricinus L., the so-called sheep tick, infests sheep and cattle in northern England. I. canisuga Johnston, alone or with I. ricinus, has been found on sheep dogs and foxes.The distribution of the sheep tick in this region is markedly discontinuous, the total infested areas including only about one-fifth of the hilly country, to which the tick is almost exclusively confined.In north-west Northumberland, tick distribution shows a significant degree of correlation with certain factors inherent in or influenced by the surface geology. Broadly speaking, where surface geology lends itself to relatively good natural drainage and soil, the grazing is relatively good and ticks are absent; and where surface geology results in relatively poor natural drainage and/or soil, the grazing is relatively poor (‘rough’) and ticks are present.No consistent correlations between soil characteristics—i.e. pH, available phosphates and potash, soil textures, mechanical analysis and soil depth—and tick distribution have been found. Nor is there a consistent correlation- between quality of natural drainage and tick distribution. The interaction of soil and natural drainage factors, however, profoundly influences the character of the vegetation layer.In the four northern counties, the same plant dominants occur on tick-infested and tick-free hill lands. Where grazing is rough ticks are usually present irrespective of whether the dominant plant is one of the rough grasses (Nardus, Molinia, Agrostis, Aira), bracken or heather; where grazing is relatively good (i.e. not rough), ticks are invariably absent.Observations on a smaller scale show that the thicker, i.e. rougher, the vegetation layer, the denser the tick population and also the thicker the vegetation layer, the thicker the basal mat. On five plots it has been shown that there is a consistent positive correlation between mat thickness and tick population density: the thicker the mat,’ the denser the tick population irrespective of whether bracken or grass is the dominant. Thus the chief controlling factor in tick distribution is the physical character of the vegetation layer.
Experiments on the mode of action of hexyl resorcinol as an anthelmintic
Authors: Trim A. R. 
Published: June 2009

1. Hexyl resorcinol penetrates readily into Ascaris lumbricoides var. suis through the cuticle.2. The rate of penetration is roughly proportional to the concentration of the drug in the medium, and is not significantly affected by changes of pH. or oxygen tension and the presence of a number of other substances, including other drugs and certain nutrient substances.3. The rate of penetration is greatly decreased by gastric mucin and certain concentrations of bile salts and soaps.4. The rate of penetration of the drug is increased by certain concentrations of sodium oleate.
A comparative study of the infective larvae of Nematodirus species parasitic in sheep
Authors: Thomas R. J. 
Published: June 2009

Three species of the genus Nematodirus have been described from sheep in Britain: N. spathiger, N. filicollis and N. battus.The infective larva of N. spathiger has been described by Monnig (1931), and in more detail by Dikmans & Andrews (1933). The infective larva of N. filicollis was described and figured by Boulenger (1915). A brief description was also given by Morgan (1930), while Maupas & Seurat (1913) figured the larva but gave no description or measurements. In the present paper, the infective larva of N. battus is described and compared with those of the other two species. However, as in the course of this study certain discrepancies were observed in the published description of the larva of N. filicollis, a redescription of the larva of this species is also given.