This collection of parasites was made in Cyprus between February 1928 and August 1929. Some were collected by Professor R. T. Leiper personally while on a visit, the remainder were sent to the Helminthology Department of the London School of Hygiene and Tropical Medicine by Dr. R. J. Roe of the Civil Veterinary Department in Cyprus. The two collections are here dealt with together. The hosts from which the parasites were taken are as follows:—horse, mule, pig, dog, cat, sheep, goat, hedgehog and fowl. Altogether the collection comprises 16 genera and 21 species of Nematoda: 5 genera and 7 species of Cestoda: and some acanthocephala, linguatulids, ticks and sarcocysts. The latter three are not dealt with here. The following is a systematic survey of the specimens.

Although several records now exist of the occurrence of Capillaria (Hepaticola) hepatica (Bancroft, 1893) as a natural infection of the wild rabbit the attempts which have been made to infect this host with eggs obtained from an infection in the rat have not been completely successful. Nishigori (1925) states that although this parasite can infect the rabbit and shew some development it does not reach maturity, while Saito (1925), in the English account of his paper given in The Japan Medical World states that “In the rabbit the larva might develop into maturity and cause pathological changes but do not multiply.”

Owing to the lack of adequate descriptions and figures, the majority of the members of the Genus Capillaria are extremely difficult to identify. This is no doubt due, to some extent, to the fact that the worms are so slender that certain morphological features upon which species can be separated are difficult to observe without a very close examination of the worms under high magnification.

It has been held for many years that the species of Syphacia found in the field mouse (Apodemus sylvaticus) and originally described by von Linstow (1884) under the name of Oxyuris stroma is the same as Syphacia obvelata (Rud., 1802)—a common parasite of rats and mice and occasionally found in man.

Three species, and one variety, of the pseudophyllid genus Bothridium de Blainville, are known to occur in pythons. B. ovatum occurs in the African python (P. sebce): B. pythonis in the Indian python (P. molurus) and B. pythonis var minor in P. reticulatus, the Indo-Malayan python; while Maplestone and Southwell (1923, p. 317) record another species, B. ornatum from the Australasian python (P. spilotes var variegatus). The literature on this genus appears, so far, to have dealt only with morphology and taxonomies. Joyeux and Baer (1927, p. 126) describe the anatomy and relationships of B. ovatum, B. pythonis and B. pythonis var. minor. Braun (1894–1900, p. 1690) gives a brief description, accompanied by very detailed figures, of the anatomy of B. pythonis and also figures the embryonated ovum (pi. Iviii, fig. 8). This is the only figure of any developmental stage of the parasite which the writer has been able to discover. Southwell (1930, p. 58) records the worm from P. reticularis and P. molurus, in Bengal, Nepal and Ceylon, and summarises its anatomy. He also mentions its occurrence in a tiger which he thinks had been eating a python. No account of the life-cycle of any species of Bothridium appears to have been written. When, therefore, in February, 1932, some living Bothridium arrived in the Helminthology Department, it was resolved to discover how far its development resembled that of other better-known Psuedophyllids.

During recent years the compounds belonging to the resorcinol series have acquired considerable importance as germicides, and among these compounds the hexyl derivative has provided the optimum working value. While this is reasonably active, a sufficient quantity can be obtained in solution for administration.

The following material was sent to the Department of Helminthology of the London School of Hygiene and Tropical Medicine in three groups; two lots coming from Mr. Aneurin Lewis, of the Veterinary Research Station at Kabete, Kenya Colony, and the third lot from the Director of Veterinary Services, Uganda. For this latter, the writer is indebted to the Imperial Bureau of Agricultural Parasitology. The major part of the material was placed at his disposal by Professor R. T. Leiper, F.R.S., to whom he wishes to express his sincere thanks.

Nematodes belonging to two distinct genera are known as the causal organisms of galls on the roots of plants. One of these belongs to the genus Anguillulina=Tylenchus and the other to the genus Heterodera. The former, under the name of Tylenchus hordei Schøyen, 1885, has been known for many years as the producer of galls on the roots of certain grasses and cereals; the latter, under the name of Heterodera radicicola (Greeff, 1872) Müller, 1884, as the producer of galls on the roots of a very large number of wild and cultivated plants both monocotyledons and dicotyledons.

The purpose of the present paper is to bring together brief descriptions of the various species of the genus Anguillulina, more generally known under the synonymous generic name of Tylenchus Bastian, 1865. In the case of the plant-parasitic species, in addition to particulars on dimensions and morphology, data are given on life-history, hosts and geographical distribution; such matters as symptoms, pathology and methods of control are not dealt with.

Some preliminary experiments on the effects of potato root excretions in stimulating the larvæ of H. schachtii to hatch and emerge from the cyst, and the neutralisation of this stimulating factor by the root excretions of mustard seedlings, have already been described. Since chemical treatment of infected soil as a means of controlling the eelworm has been the subject of investigation in Europe for the past fifty years without yielding any results of practical value, investigations into the reactions of the paiasites to the root excretions of plants were undertaken in the hope that some result might be attained which would point to a solution of the eelworm problem on biological lines. The high degree of specialisation shown by the British potato-strain rendered it peculiary suitable for investigations of this character.

In 1890, Müller described, from the lung of the cat, a species of nematode which is now known as Aelurostrongylus abstrusus. In 1928, I was able to show that its true habitat was not the lung substance, but the pulmonary artery and its branches, and that its pathogenic action, was mainly, if not entirely, due to the presence of the developing eggs and larvae distributed throughout the lung tissue by the blood stream.

The grey squirrel (Sciurus carolinensis), although of comparatively recent introduction from North America, has become thoroughly acclimatised and may now be regarded as one of the native British Mammals. Comparatively little is known of its helminth parasites and the following oxyurid, found in the large intestine of a specimen shot in the north of Scotland, appears to be undescribed.

In a paper published in 1925, the writer described the anatomy of the adults of this parasite and amplified Schøyen's account of it. At the same time it was shown that infective material derived from Elymus arenarius could give rise to galls on the roots of barley and Poa annua. Kemner (1930) has quite recently shown experimentally that the parasite from barley can set up galls on E. arenarius and presented important data on the agricultural significance of the parasite in northern Sweden. Detailed information as to which is infective stage of the parasite and on its life-history have so far been lacking and in order to remedy this omission the writer made a number of observations and carried out certain cultural experiments during 1927 and in the months of July, August and September 1931. These latter were made possible by the arrival during July of a good supply of galled roots of Elymus arenarius received in a living condition.

During a recent expedition carried out by Dr. W. K. Blackie and Mr. W. A. McDonald in Southern Rhodesia, large numbers of the snail Bulinus tropicus were collected for living storage in aquarium tanks in the Medical Zoology Division of the London School of Hygiene and Tropical Medicine. They were collected about the 20th February, 1931 and were brought to London on the 30th March and were distributed amongst several separate tanks. Some five weeks later some of the snails were overtaken by a curious sickness which gradually but rapidly spread to the rest and within a fortnight of their first appearance, the characteristic symptoms were present to a greater or less degree in almost every one of the snails, which numbered several hundreds. The sickness proved fatal in many cases and towards the end of three weeks the mortality was nearly 50 per cent. Thus it appeared likely that the whole collection would eventually be destroyed when the epidemic, as it seemed to be, spent itself with surprising suddenness and the remaining snails made a rapid recovery.