Historical.—Our knowledge of the cestode parasites of marine fishes is due almost entirely to the work of Linton in North America, Shipley, Herdman and Hornell in Indian waters, Zschokke and Beauchamp in Europe. We know nothing regarding the tapeworms found in fishes in South America, round the coast of Africa, or in the Arctic; and our knowledge of those found in the Far East is limited to descriptions of about ten species by Yoshida. It will, therefore, be apparent that there still remain large areas to be investigated.

1. The sera of 18 goats were investigated for the bilharzia complement fixation reaction, using as antigen alcoholic extract of the livers of snails (Planorbis exustus) infected with cercariae of S. spindale.

2. The sera of 5 out of 7 goats harbouring S. mattheei, and of 4 out of 4 goats exposed to alimentary infection with S. bovis yielded positive results, the range of complement fixation varying from 5 to 20 M.H.D.'s.

3. The sera of non-infected goats and of 3 goats exposed to infection with cercariae of S. mansoni from which these animals appear naturally immune, yielded negative reactions.

4. The complement fixation reaction with cercarial antigen (S. spindale) has now been applied to infestation with 3 human and 4 cattle schistosomes, and its group applicability to mammalian schistosomiasis may be regarded as proven.

In the early spring of 1931 one or two hibernating adults of Phyllotrela undulata Kutsch., recovered from a piece of tree bark, were dissected by chance and found to be parasitized by a nematode. Realising that the host insect was not only of wide distribution throughout the country but also that, amongst farmers and other crop growers, it was known as a serious and destructive pest, this accidental record of parasitism led the writer to enter upon the present study.

In April, 1931, a collection of helminth parasites was received by the Imperial Bureau of Agricultural Parasitology from Mr. Bodkin, the Government Entomologist at Jerusalem. The specimens appear to have been collected by Native Meat Inspectors from slaughter houses, farms, etc., ranging through eleven different localities, from Hebron and Gaza, west of the Dead Sea, in the south; to Acre and Safad, north of the Sea of Galilee. The collection comprised 117 bottles of material, much of which had been rather poorly preserved. For such a large assortment of material the number of species is relatively small, as so many of the parasites were sent in duplicate. There does not appear to be any species new to science, and the following note is intended as a contribution to the zoögeography of a country whose parasitic fauna is somewhat inadequately known.

Before dealing in detail with certain aspects of the research work on the potato eelworm which has been carried out by the present writer an account of the occurrence of the parasite in Ireland must be given.

(1) Experiments have been conducted to investigate the part played by Vitamin A in the prophylaxis of helminthiasis. Heterakis gallinæ in the chicken and Parascaris equorum in albino rats were used.

(2) The evidence tends to show that in Heterakis infestation the vitamin content of the diet has no effect on the course of the infestation. In Ascariasis in rats, however, the vitamin affects significantly the hatching, survival and rate of development of the larvae within the host.

(3) The writer can put forward no reason for this difference except to suggest that it may lie in. the life history of the parasites. Considering her own results and those of previous workers as cited in the introductory part of this paper, it seems obvious that the vitamin is effective in cases where the parasite comes into close contact with the host tissues.

(4) Some notes on the viability of eggs are added.

During the course of some experiments involving the Nematode worm Heterakis gallinæ, it became necessary to know the exact life history in order to interpret the results. On consulting the literature it became evident that the details of the life history had never been worked out accurately in either this worm or in any of its near relations. Further-more, there was considerable controversy on the subject. For this reason therefore the whole morphology and life history were investigated in detail and some interesting points came to light.

RECENT investigations carried out by the senior writer on the incidence of parasitic helminths in the alimentary tract of sheep in the north of Scotland have demonstrated heavy losses in lambs due to parasitic gastritis. In the autumn of 1932 six severe outbreaks were recorded in the counties of Kincardine, Aberdeen and Moray, but no doubt this number would have been greatly exceeded had it been possible to make a comprehensive survey. Some idea of the severity of the disease may be judged by the fact that several farmers lost from 10–20 per cent, of their lambs.

Dogs are notoriously susceptible to helminthic infections, especially of the alimentary tract. Their role as carriers of such important pathogenic organisms as Echinococcus and Taenia multiceps makes the study of their parasites of more than academic importance, so much so that by an order of the United States Bureau of Animal Industry, all sheep dogs imported into the U.S.A. have to be held in quarantine pending a faecal examination for helminthiasis (Wigdor, 1919). Statistical surveys of the helminth parasites carried by dogs have already been made in a number of different countries. In this country the subject has been studied by Lewis at Aberystwyth, in Wales; and by Nuttall and Strickland in Cambridge. Brown and Stammers have made a parasitological survey of the dogs in London based on post-mortems combined with examination of faeces from London pavements.

1. Plerocercoid larval stages of Diphyllobothrium latum (Linn.), in 0·2 molar sodium chloride can tolerate temperature values between −8° and 55°C., the survival time varying from 15 minutes at 54° C. to 60 hours at 20° C., and diminishing gradually from 24+ hours at zero to non-survival at −8°C. The optimum range of values lies between 38° and −2·8° C. It is suggested that the median point of the optimum range approximates to the mean summer temperature of the host fish and that variations in temperature from this mean point restrict the survival time value of the intramuscular plerocercoid phase.

2. They can tolerate concentrations of HCl between 0·3 and 0·001 molar if 0·5 per cent. of pepsin be present, and concentrations of Na2CO2 between 0·2 and 0·001 molar, when 3 per cent. of pancreatin is present, for the length of time they would normally be subject to canine or human gastric and duodenal digestion.

3. They can tolerate the component salts of Ringer-Locke solution when in concentrations between 0·2 and 0·001 molar for periods of time varying with the concentration and with the chemical structure of the salt. The addition of other electrolytes to decimolar NaCl does not increase its value as a medium for the larvae.

4. The behaviour of plerocercoids in electrolyte solutions of 0·2–0·001 molar concentration is essentially similar, and initial period of activity being followed by a period of contraction and latent mobility—which, however, may be omitted—passing into a period of endosmotic immobility and disintegration. It is suggested that activity is stimulated by the influence of absorbed CI' upon muscular irritability and that depression of activity is induced by absorption of the kation of neutral salts or of the whole molecule of acids or alkalies.

Looss (1898) described a trematode, Distomum reniferum, from the intestine of a turtle, Trionyx nilotica. Later, while reviewing the genus Distomum of Retzius, 1782, the same author (1899) described a new form, Astia impleta, from the intestine of Tetrodon fahaka and also transferred his former species, Distomum reniferum as a type species of this new genus Astia. The generic name was subsequently changed to Astiotrema Looss, 1900 and both the species described originally under Astia are now included under this new name. Odhner (1911) redescribed both the species and added considerably to our account of these forms. Other species have since been added to the genus Astiotrema. The latest addition to our knowledge of the genus Astiotrema is that by Mehra (1931) who has given an interesting account of two new species from the tortoises of Allahabad, and has, besides, given a very useful table and key for the identification of the various species of the genus under review. The present paper deals with an account of another new species of the genus obtained at Lucknow, from the intestine of a tortoise, Chitra indica, from the river Gomti.

ALTHOUGH some marsupials are insectivorous or carnivorous in diet many others are vegetarian in diet and frequently cause appreciable damage to pastures and crops and therefore are of considerable economic importance. Recently, during the course of searching the literature for references to helminth infections in marsupials it was observed that, in certain cases, hosts other than marsupials were involved and in some instances were of economic importance in that they were domesticated animals. Whether or not marsupials assist in the spread of parasitic infection is somewhat inadequately dealt with in the literature but one cannot lose sight of their acting as reservoir hosts.

About the middle of July, 1932, red galls were discovered on blades of grass in a meadow at Winches Farm, St. Albans, by Mr. W. A. Macdonald, who drew the attention of the writer to the presence of nematodes within them. Subsequent search on this and an adjoining meadow proved that the galls were widely distributed, on the same kind of grass, over the whole area, whilst some days later similar galls were found on a bank by the side of the main road from St. Albans to Hatfield. The grass was identified as Agrostis tenuis Sibth. (Agrostis vulgaris With.), popularly called Fine Bent-grass.

Filaria ozzardi Manson, 1897, or as it is recently but less familiarly known, Mansonella ozzardi, was first described in its larval stage, having been found in the blood of Caribs of British Guiana. The adult form of which the female only was found by Daniels (1899) in the subperitoneal connective tissue of Indians from the same region, is very inadequately described.

The material upon which this addition to the ever-growing genus Enlerobius is based, was collected from the cæcum and large intestine of two marmosets which died at the London Zoological Gardens during the winter of 1931–32. The material came to me in the course of the routine examination of Helminthological material from the Prosectorium, and as the genus is one of importance in relation to human hygiene, this species seems to the writer to merit a brief description.

The hermaphroditic Trematodes from the blood vessels of the turtles are included under the Family Spirorcbidae and represent several genera differing from each other in several features, including the general topography of the genital organs. It originally contained only two genera—Spirorchis and Hapalotrema, differing from each other in the number of suckers, the relative position of the genital glands and the number of testes. Owing to these unique differences between them they were referred by Stunkard (1921) to two subfamilies—Spirorchinae and Hapalotreminae. The work prior to 1923 is summed up by Stunkard (1923) in a brilliant memoir, where, besides describing two new genera, one under each of the two subfamilies, from North American turtles, he has clearly elucidated some important points of systematic nature. Subsequently, the same author has considerably added to our knowledge of the group in several memoirs mentioned in the list of references at the end of the present communication.

In June, 1931 a small collection of parasites from the Prosectorium of the Zoological Gardens of London was found to contain a number of long slender filaria worms from the peritoneal cavity of a tree Kangaroo. Upon examination these worms appeared to represent a new species of the genus Breinlia which was erected by Yorke and Maplestone in 1926 to contain Filaria trichosuri Breinl, 1911 (not 1913 as quoted by Yorke and Maplestone), from the abdominal cavity of the Australian opossum (Trichosurus vulpecula Kerr).

During the examination of numerous specimens of Bilharzia collected from domesticated and wild ruminants in this Territory a species of bloodfluke, closely related to the vector of intestinal bilharziasis in the Far East, was observed. For this species the name Bilharzia margrebowiei sp. nov. is designated in honour of my wife, Dr. Margaret Gregor Leroux (née Bowie), for the self sacrificing way in which she has assisted me in the past.

The developments which have taken place during recent years in the scientific management of grassland have resulted in a marked improvement both in the quality and in the quantity of the herbage produced. This has been brought about partly by frequent manuring, particularly with nitrogenous manures, and also by ensuring the close cropping of the grass at frequent intervals.