bluuebunny/crossref_metadata_2025_split huggingface dataset:
Considerations on the Life-history of Tapeworms of the Genus Moniezia
Authors: Flattely F. W. 
Published: June 2009

Lambs contract Moniezia infection either at or very soon after birth, since they have been observed to harbour adult worms at 2–3 months old and in one case, to pass proglottids at 4–6 weeks.The intermediate host, if such exists, must be frequent on the pasture in early spring, otherwise lambs would not be found to harbour adult tapeworms so regularly or in such numbers when slaughtered in early summer. In the small intestine of a lamb from 3–4 months old slaughtered at Aberystwyth, there occurred 75 individuals.The fact that lambs regularly harbour adult tapeworms before they are weaned suggests the possibility of their contracting the infection from the mother-ewes. No direct evidence in this direction has been obtained, however, and an attempt to produce a larval stage in the udder region of a ewe by feeding to it the eggs of a tapeworm proved abortive.Hitherto, all attempts to produce the adult tapeworms directly by feeding the eggs to sheep have failed; there is, however, the remote possibility that the eggs require to undergo some kind of maturation process outside the body of the sheep before they will develop. The fact that several species of Moniezia occur in the domestic sheep would seem to require an intermediate stage, which would occur in a corresponding number of intermediate-host species.The disease seems prevalent in flocks which are singularly free from ectoparasites.The invertebrates which seem most likely to harbour an intermediate stage are coprophagous insects, etc. (beetles, flies, mites). Attempts to infect species of Aphodius have nevertheless proved fruitless.Moisture favours the survival of the eggs of Moniezia: eggs kept in water for a period of several months seemed to remain perfectly viable. Nevertheless tapeworm is common among flocks on pastures about Rome which are characteristically dry.A comprehensive series of experiments under conditions of the most complete control would almost certainly clear up the life-history; on economic grounds alone the problem is urgent.The overwhelming majority of a quantity of worms collected from slaughter-houses in Aberystwyth, Aberdeen, Beauly (Inverness-shire) and Newcastle-on-Tyne proved to be of the species M. expansa. The only other species found were M. trigonophora and M. alba. The identification was based on anatomical characters and not on externals, which are useless.The writer intends directing his attention to coprophagous mites as carriers, viz. Gamasus coleoptratorum, G. fimetorum, Macrocheles glaber.
The Action of Hydrochloric Acid upon Cultures ofTrichomonas
Authors: Bishop Ann 
Published: June 2009

The question of the mode of transmission of theTrichomonasof man from one host to another is of particular interest because no authentic encysted stage is known.Many workers have attempted to infect “clean” animals by the mouth with active trichomonads from a variety of hosts, either from cultures or directly from faeces. The results are conflicting. Thus Escomel (1913) fed faeces containingTrichomonas intestinalis(= T. hominis) from a human case of dysentery to a rabbit, a guinea-pig, a cat, and a dog, and obtained a positive result in the dog. He does not, however, state that he examined his animals, to find whether they had any similar natural infections, before performing his experiments. Boyd (1919) fed a culture ofTrichomonas intestinalis(= T. hominis), mixed with milk, to a white rat and infected it. He had previously examined this rat and one used as a control and found them to be free from this flagellate. He was, himself, uncertain whether the infection was due to the free flagellates or their “cysts“ which he says were present in the culture. The cysts figured by him (Plate XI, figs. 7–17) appear to be rounded-up and degenerating trichomonads. Pringault (1920) fedTrichomonas intestinalis(= T. hominis) to a cat, a guinea-pig, a rabbit, and a white rat, without establishing an infection in any one of them.
A Survey of Human Intestinal Protozoa in Sweden and Finland. (A Preliminary Report)
Authors: Svensson Ruth M. 
Published: June 2009

This survey records the intestinal protozoa found in 611 hospital cases in Sweden, 1244 mental asylum cases in Sweden, and 159 medical out-patients in Finland. Only one examination was made of each case.In each of these three groups the following protozoa were found:Entamoeba histolytica, E. coli, Endolimax nana, Iodamoeba bütschlii, Giardia intestinalis, andChilomastix mesnili. In hospital and asylum cases in SwedenDientamoeba fragiliswas encountered,Trichomonas hominisand a small flagellate were found in the asylum group, and in this group as well as in the series in Finland,Balantidium coliwas met with. In one case cysts of this protozoon were found.In a group of 46 cases, formed stools as well as loose stools obtained after administration of a purgative were examined. The loose samples revealed the presence ofTrichomonas hominis, Balantidium coli, and a small flagellate, none of these having been found in the formed specimens. The percentage ofDientamoeba fragilisrose from 8·7 per cent, in the formed stools to 23·9 per cent. in the loose stools. All the other species were more abundantly present in the loose than in the formed samples.In Sweden, mental asylum cases show a much higher incidence of infections than do the hospital cases.Intestinal protozoa seem to be more common in Finland than in Sweden.Among hospital cases in Sweden the residents of Stockholm show a lower incidence of infections than do the people living in rural districts.At admission, asylum cases are not infected to a higher degree than are the general hospital cases. The rise in incidence of infection is directly proportional to the length of time spent in the institutions up to ten years, after which time no further increase occurs. The male patients show throughout considerably higher percentages of infections than the female patients.Chilomastix mesnilishows a very high incidence in the asylums, whereas the percentage ofGiardia intestinalisremains practically the same throughout the time of confinement in the institution.
Coccidian oocysts
Authors: Goodrich Helen Pixell 
Published: June 2009

1. The spores of Eimeria (not the oocysts) are the real infective agents and, as in other Sporozoa, they readily set free their sporozoites in the duodenum or in vitro under suitable conditions.2. The protective oocyst has double walls: the ectocyst is thick and impervious to fluids but easily fractures by mechanical means, such as drying. Even though cracked, it may continue to protect the thin endocyst and spores until they reach the specially muscular regions of the alimentary canal. Free spores are probably also sometimes ingested.3. The ectocyst is a continuous envelope without a persistent micropyle. It resembles keratin in many ways.
The ecology of the sheep tick, Ixodes ricinus L. Host availability and seasonal activity
Authors: Milne A. 
Published: June 2009

In three experiments, the chief hosts, sheep, were withheld from a grazing until 0–3 weeks after the normal spring peak of female tick activity. This did not give rise to any appreciable prolongation of female tick activity into the normal summer offseason. More than half the female ticks actually available during the entire spring season were unfed when activity came to an end. This was due to the withholding of hosts. Hence that aspect of the ‘two-brood’ theory which claims that activity ends in spring, because all the available ticks are fed, is untenable as the complete explanation of bimodal annual activity.Increase in sheep-stocking density, over the normal for a grazing, lowers the average infestation per sheep for that season at least.The experimental data suggests the following:(i) Delay in stocking a grazing with sheep results in a slightly higher-than-normal population of active female ticks which is fairly quickly absorbed after reintroduction of sheep.(ii) A varying proportion of the tick population becomes active each week throughout the tick season, increasing up to the peak and decreasing thereafter.(iii) The average duration of individual activity in a natural population of female ticks is probably not more than 1 month, perhaps less.Practical applications of the findings to hill sheep farming are indicated.
On the Life History of Ascaris lumbricoides, L. Part V
Authors: Stewart F. H. 
Published: June 2009

Since the publication of Part IV (Stewart, 1919), four papers dealing with the life-history of Ascaris lumbricoides have appeared.(1) Ransom and Foster (1920) give a full account of their work, preliminary reports of which have already been published (1917 and 1919).As evidence in the problem of whether the worm can undergo full development in one host alone, they attach great importance to two experiments, one on a kid and one on a lamb, in which after the administration of ripe eggs of A. suilla, they recovered worms from the intestines. In the kid, which died 24 days after the first feeding, the worms measured from 4·3 to 11·4 mm.; in the lamb, which was killed 103 days after feeding, the worms measured from 60 to 110 mm. The authors consider that, as Ascaris infection is uncommon in goats and sheep, the worms may without doubt be ascribed to the experimental feeding. They record five experiments on pigs which gave doubtful results, since the pigs fed with Ascaris eggs were found, after varying periods, to be on the average less infected with Ascaris than pigs which were kept as controls, and had not been so fed.
Life cycle of Coitocaecum anaspidis Hickman, a New Zealand digenetic trematode
Authors: Macfarlane W. V. 
Published: June 2009

The life cycle of Coitocaecum anaspidis involves three important stages. The adult occurs in Galaxias brevipennis, G. attentuatus, Gobiomorphus gobioides, and in specimens of Anguilla spp. less than 30 cm. long. Potamopyrgus antipodum and P. badia are the molluscan hosts of the sporocyst and cercaria. In New Zealand the cercaria attacks and encysts in Paracalliope fluviatilis, and in Australia in Anaspides tasmaniae. A metamorphosis of the cercarial larva into a progenetic metacercaria takes place in the amphipod.Paracalliope does not become infected with Coitocaecum till the crustacean has reached 2·0 mm. in length. The thigmotropism of the Paracalliope fits exactly with the ground-living habit of the stumpy-tailed cercaria. The small river fish feeding in slack water acquire Coitocaecum from Paracalliope.
Studies on the germ cell cycle of the digenetic trematodeParorchis acanthusNicoll
Authors: Rees Gwendolen 
Published: June 2009

1. The anatomy of the male and female genitalia ofParorchis acanthusis described in detail. An extensive receptaculum uterinum occurs in the female system.2. The chromosome number inP. acanthusis twenty-two.3. Spermatogenesis, oogenesis, and fertilization, are described in the adult worm. The chromosome number in both male and female cells is reduced to eleven at the first meiotic division.4. Maturation in the female takes place in the “receptaculum uterinum”.5. Cleavage of the ovum to the three cell stage has been followed.6. The probable synonymy ofP. acanthusandP. avitusis discussed.
Observations on a monocystid gregarine, Apolocystis elongata n.sp., in the seminal vesicles of Eisenia foetida (Sav.)
Authors: Phillips Nada E. , Mackinnon Doris L. 
Published: June 2009

1. A new monocystid gregarine is reported from the seminal vesicles of brandling worms, Eisenia foetida Sav. The morphology and movements of the trophozoite are described, and the stages of gametogony and sporogony are outlined.2. The chromosome cycle is investigated. The haploid number of chromosomes is four, and the reduction division is shown to be zygotic.3. The systematic position of the gregarine is discussed, and it is placed in the genus Apolocystis as A. elongata n.sp.
The transmission of a plant virus complex by aphides
Authors: Smith Kenneth M. 
Published: June 2009

An account is given of experiments on the aphistransmission of the composite virus disease of tobacco known as rosette. It is shown that the component viruses—the vein-distorting and mottle viruses—persist for long periods in the body of the aphis, and that as many as twenty consecutive tobacco plants can be infected in 24 hr. serial transfers without the insect having recourse to a fresh source of virus.The aphis Myzus persicae is the most efficient vector, the aphis M. convolvuli being less effective. The aphides M. circumflexus and Macrosiphum gei failed to transmit the virus.It is shown that the mottle virus can only be transmitted by the aphis when it is accompanied in the plant by the other component of the rosette disease, the vein-distorting virus. The latter virus is easily transmitted by the aphis, either alone or in combination with the mottle virus.The writer's best thanks are due to Miss Margaret Short for her assistance with the large numbers of aphis-transmissions, and to Dr Douglas Lea and Dr Roy Markham for suggestions in the course of the work.
Notes on Breeding Fleas, with Reference to Humidity and Feeding
Authors: Sikes Enid K. 
Published: June 2009

Experiments were carried out to show the different hygroscopic properties of certain foods supplied to flea larvae. These show that larvae of Ceratophyllus wickhami require about 15 to 28 per cent, of water in their food. Dried blood, albumen (blood) and material from the bottom of a squirrel's nest were used.Newly hatched flea larvae were fed on different substances at varying humidities and a constant temperature. A relative humidity of 80 per cent. gave the best results.Dried blood is a convenient food for breeding flea larvae in the laboratory, and may be used with or without a mixing medium, such as sand. Albumen is a more simple food on which a few larvae will survive, but at lower humdities than dried blood.Flea larvae will eat a great variety of other foods, including squirrel faeces, ground-up cockroach and dead adult fleas, but these do not provide a complete diet.It does not seem necessary for the larvae to have dried blood from the host of their parents, rabbit or human blood being quite as satisfactory.
Some Observations and Experiments on the Biology of Larval Trematodes
Authors: Rees Gwendolen 
Published: June 2009

1. Experiments on the liberation of cercariae from their snail hosts have shown that under normal conditions C. limbifera (Seifert) and Cercaria “Z” n.sp. emerge during the day-time only, while in C. cambrensis I (Wright) the emergence takes place during the whole twenty-four hours, but considerably more so during the night-time.Continual darkness causes a decrease in the numbers emerging, and a lowering of the temperature partially or completely checks the escape of the larvae.In Cercaria “Z” there is a double maximum between 11 a.m. and 4 p.m. in the numbers liberated.The invasion of L. truncatula by the larval stages of Fasciola hepatica leads to the disintegration of the host's tissues, the appearance of black pigment and the reduction of the liver cells to a thin layer of protoplasm containing the nuclei.
Studies on the Influence of the Environment on the Sheep Blow-fly, Lucilia sericata Meig
Authors: Evans A. C. 
Published: June 2009

The length of life at various humidities of unfed flies and of flies fed for 1 day and 6 days on diets of meat, sugar and water, sugar and water, meat and water, and water alone, is discussed. The continued feeding of flies on a diet of meat, sugar and water brings about a shortening of their life at all humidities when the flies are starved owing to their increased rate of metabolism. Flies fed on sugar and water are more resistant to humidity than flies fed on meat, sugar and water, and the females are more resistant than the males. Flies fed on meat, sugar and water lose weight more rapidly than flies fed on sugar and water.High humidity is more favourable for growth of the ovaries than low humidity. Humidity has no effect on oviposition at temperatures of 10–35° C., but at 40° C. low humidity is unfavourable.
Researches on the Intestinal Protozoa of Monkeys and Man
Authors: Dobell Clifford 
Published: June 2009

(A) Enteromonas hominis Fonseca, 1915 (emend. Dobell, 1921) is the correct designation of the flagellate first adequately described as Tricercomonas intestinalis by Wenyon and O'Connor in 1917.Organisms morphologically indistinguishable, at all stages in the life-cycle, inhabit various macaques (M. rhesus, M. sinicus, M. nemestrinus). I have grown the simian species in “pure” cultures, and have obtained all stages in vitro and in vivo: and I have also obtained evidence—not “experimental ”, but from observed spontaneous spread of infection—that the species in M. rhesus and M. sinicus, at least, are identical.An attempt to infect a man experimentally, by oral administration of cysts from a pure culture of the simian species (from M. sinicus), was unsuccessful.(B) Embadomonas intestinalis [ = Retortamonas Wenrich nec Grassi] is probably the correct designation of the flagellate described by Wenyon and O'Connor (1917) as Waskia: and it is the only intestinal protozoon of Man which can be readily cultivated at all temperatures from 15° to 38° C. This species closely resembles several others described from other vertebrates—both warm-blooded and cold-blooded—but the identity of them all is still questionable.A species similar to E. intestinalis has been observed in macaques by several workers, and has been assumed to be identical on insufficient evidence. Two attempts which I have made to infect macaques (M. rhesus and M. sinicus) experimentally, by feeding on cysts in pure cultures of E. intestinalis from Man, were completely negative.(C) Consequently, while it seems probable on general grounds that both the Enteromonas and the Embadommas of men and macaques are specifically identical, it is still premature—with only negative evidence for their transmissibility from host to host—to assert this conclusion as a fact.
The occurrence of Rickettsia-like bodies in the Reduviid bug Triatoma rubrofasciata and their transmission to laboratory animals
Authors: Webb J. Lewis 
Published: June 2009

1. Rickettsia-like bodies are recorded from the reduviid bug, Triatoma rubrofasciata.2. These Rickettsiae are capable of being transmitted hereditarily and have been found in the unhatched embryos and larvae of the bug.3. They produce pathological lesions in laboratory animals and can be maintained for at least five passages through guinea-pigs.
The inactivation of plant viruses by radiation
Authors: Lea D. E. , Smith Kenneth M. 
Published: June 2009

Experiments on the inactivation of various plant virus preparations by ultra-violet light and by X-rays are described. The curves obtained by plotting against the dose of radiation the number of lesions obtained on inoculation of a test plant are exponential and the rate of inactivation is proportional to the intensity of the radiation. The inactivation curves obtained with preparations of a given virus in different states of aggregation do not appear to be systematically different.The discussion of these results shows that the particles in an aggregated virus suspension cannot be considered to be permanent clusters of elementary virus particles. Two possible alternatives which are compatible with the radiation experiments are discussed, either (a) the aggregation consists of the attachment of a single elementary virus particle to inert matter, or (b) the aggregation consists of a reversible union of elementary virus particles, there being a dynamic equilibrium between the aggregates which are constantly dissociating and the elementary particles which are constantly aggregating. The dose of X-radiation required for inactivation of the virus is consistent with the view that inactivation is caused by the production of a single ionization in the elementary virus particle, the size of which is approximately known from nitration experiments.
The ecology of the sheep tick, Ixodes ricinus L. Some further aspects of activity, seasonal and diurnal
Authors: Milne A. 
Published: June 2009

The idea has been mooted that the sheep tick (Ixodes ricinus L.) is active at different times on different host species. Tick-activity curves for sheep, deer, hare, rabbit, skylark and meadow-pipit are similar in form and timing. With these animals, therefore, there is no indication of any marked individual species effect on activity.Where spring activity occurs, males, females and nymphs usually have similar and concurrent activity curves, but nymphs may occasionally have their peak 2–3 weeks later than adults. Larval activity is always later, the peak being several weeks after the female peak. The data for nymphs amend the general statement on activity in a previous paper by the present author.Ticks are active during the hours of darkness but the activity-density then is considerably less than in daylight. This diurnal fluctuation in activity seems to follow fairly closely the diurnal fluctuation in atmospheric temperature.
The second ecdysis of Trichostrongylus retortaeformis (Zeder)
Authors: Crofton H. D. 
Published: June 2009

(1) Ecdysis of the infective larvae of Trichostrongylus retortaeformis was induced by the action of pepsin.(2) Exsheathment occurred by the loss of the anterior cap.(3) pH 4−5 is shown to be the most favourable pH for eedysis and survival. This pH is within the range quoted for the stomach contents of rabbits.(4)Eedysis was complete in the majority of larvae after 60 hr.
The life cycle of Stegodexamene anguillae n.g., n.sp., an allocreadiid trematode from New Zealand
Authors: Macfarlane W. V. 
Published: June 2009

1. A new genus of trematode (family Allocre-adiidae) from the intestine of freshwater eels is described, and named Stegodexamene anguillae.2. The genus is related to Aephnidiogenes, Lepidapedon and Neophasis, but differs significantly from each of them.3. The life cycle followed is from the adult in Anguilla dieffenbachii to the redia in Potamopyrgus antipodum (fresh-water gastropod). The cercaria encysts in the eloetrid fish Gobiomorphus gobioides.4. Progenetic production of eggs and spermatozoa occurs in the metacercariae.5. Metacercarial excretory spherules are composed of calcium carbonate.
Antagonism of Spirillum minus infection in rats towards Trypanosoma lewisi and T. equinum
Authors: Tate P. 
Published: June 2009

1. Rats infected with Spirillum, minus are strongly resistant to infection with Trypanosoma lewisi and T. equinum if inoculated with these parasites shortly after inoculation with Spirillum minus. The resistance is most highly developed for a period of from 2 to 4 weeks after inoculation with S. minus.2. Simultaneous inoculation of rats with S. minus and either of the trypanosomes does not influence the course of the resulting trypanosome infection.3. Rats inoculated with Trypanosoma equinum during the period of acute infection with Spirillum minus develop only a very slight transient primary infection with the trypanosome and may survive for many weeks, up to 49, whereas control rats die in 5–17 days. Usually the resistant rats ultimately die from a relapse of the Trypanosoma equinum infection.4. Similarly, in rats inoculated with T. lewisi during the resistant phase due to an infection with Spirillum minus, the primary acute infection with the trypanosome is suppressed and the rats develop a slight or subpatent infection.5. The non-specific resistance to trypanosomes conferred by the acute S. minus infection soon disappears and is replaced by a specific trypanosome resistance which is active only against reinoculation with the same species of trypanosome. Thus, in this phase of resistance, a rat infected with Trypanosoma equinum is refractory to reinoculation with T. equinum but has no resistance to superinoculation with T. lewisi. Conversely, a rat infected with T. lewisi is refractory to reinoculation with that species but it is as susceptible to superinoculation with T. equinum as a normal rat.