Several specimens of this parasitic nematode were collected from the lungs of a common British Toad (Bufo vulgaris). They were examined alive, when it was at once apparent that the anterior end was different from that of R. bufonis, in that the body-wall was swollen almost to a sphere and the surrounding cuticle was correspondingly much inflated. It was also noticed that the oesophagus had a slight bulbar swelling towards its anterior end not present in R. bufonis.

A Recent study by the writer (1924) on the type species of the genus Œsophagostomum, O. dentatum, from the pig, has brought to light certain interesting anatomical features and shown the desirability of a closer examination of the members of the genus occurring in other farm animals.

Three species of these are well known, namely, O. columbianum, O. radiatum and O. venulosum, and have been dealt with fairly completely within recent years by Ransom (1911) and Railliet and Henry (1913), but even in the accounts of the worms given by these authors, there are certain differences concerning details of structure, which suggest the need for further investigation. Again, in studying O. dentatum, it was found that the genital cone of the male had a well defined structure, and it seemed of interest to determine whether the genital cones in the other species were built on the same general plan as that of O. dentatum, and whether they possessed specific differences from it and amongst themselvse

Two young pigs used by the writer in an attempted experimental infection with Necator americanus proved to be carrying a natural infection of Œsophagostomum dentatum. At the post-mortem examination, one of the animals had 35 females, 22 males, all mature worms, in the cæcum and large intestine, whilst two pairs were in copula. From the cæcal contents of the other pig, one immature female worm was obtained. No nodules were found in the walls of the cæcum or of the large intestine. Droppings containing the eggs of the parasite had been collected for a short time prior to the killing of the pigs, and were used for the cultivation of the larvæ.

1. Infection with Dibothriocephalus latus for as long a period as nine months or with as many as three worms, apart from diarrhoea in the early stages does not necessarily give rise to any symptoms which would suggest the presence of the parasite.

2. In these experimental cases a definite train of symptoms, i.e., constipation for a period of one or more days followed by diarrhcua marked the onset of complete sexual maturity of the parasite.

3. No appreciable anaemia was produced, nor was there a definite diminution of erythrocytes.

The members of the nematode genus Rhabdias present many features of great interest to the parasitologist. They are usually found inhabiting the lungs of amphibians and reptiles where their eggs or larvæ are produced. They have the general appearance of females and are either hermaphroditic or parthenogenetic in function (vide Goldschmidt, 1923, p. 176, on “Unisexual Monœcism”). Seurat (1920), p. 121, considers that the parasitic forms of R. dujardini and R. entomelas from the Slow worm Anguis fragilis are parthenogenetic females and not protandrous hermaphrodites because they lay an enormous number of eggs, whereas the hermaphroditic forms produce comparatively few eggs. Moreover, in R. entomelas he has been unable to find either receptacula seminis or spermatozoa.

The material on which this paper is based was received by Prof. R. T. Leiper from several sources, and includes specimens collected in British Guiana by the Filariasis Commission, in West Africa by Dr. Yale Massey, and in New Guinea by Dr. G. M. Heydon. In addition there was a tube received from Dr. O'Connor from Samoa labelled on the outside of the bottle “Pig, Samoa, Ank. Duod. from intestine,” and inside (presumably by Dr. Clayton Lane) “Crassisoma samoense.” It contained specimens of the latter species only. The type material of Lane's two new species from the pig was also available for examination.

Since the beginning of October, 1923, the writer had the opportunity of collecting helminths from 25 horses slaughtered in Edinburgh, and from 20 horses and one donkey slaughtered in London.

The Edinburgh material was collected during the months October, November and December from aged horses, the London material during February, March and April, likewise from aged horses and from a very old donkey. The donkey was found to harbour at least 26 species of nematodes, 15 of which have not hitherto been recorded from England.

From the horses examined in London, 38 species of helminths were obtained, 19 of which are new to England, and in Edinburgh 38 species, 11 of which have not hitherto been recorded from Scotland.

The earliest account of the Strongylid parasites of the rhinoceros is given by von Linstow (1907) where he describes the only form under the name Deletrocephalus stylosus. His description of this type is brief and now inadequate and the illustrations are very few. This form, however, does not show any generic characters in common with the type species, Deletrocephalus dimidiatus, Diesing, of the genus. It was, hence, removed by Skriabin (1916) into a new genus, Kiluluma, created by him for its reception. Thus the form, D. stylosus, von Linstow, was transferred to the genus under the title K. stylosa. It may, however, be mentioned that Skriabin in his account suggests that von Linstow's Deletrocephalus brachylaimus from rock-rabbit is the probable, second species of this new genus, Kiluluma.

In the following report 38 species of helminths from vertebrate hosts are considered, of which three are new. All were collected by Dr. C. Bonné of Surinam, and were presented through Prof. Leiper, F.R.S., to the London School of Tropical Medicine. The writer wishes to express his thanks to Prof. Leiper for the privilege of examining this material.

Thanks to the kindness of Professor Leiper, opportunities were given to measure the red cells in these three cases of experimental Dibothriocephalus infection, and to construct Price Jones curves to show the distribution of the cells. In addition, Dr. J. Smith kindly supplied blood films and the particulars of a case of natural infection occurring in an Esthonian sailor, C. E., who was under his care in the City Hospital, Aberdeen, and which had been diagnosed by Prof. Leiper.

It is commonly asserted in the text books that the anaemia which occurs in cases of infection with this worm is identical with that found in pernicious anæmia. It seemed worth while, therefore, to see if there occurred the increase in the average mean diameter of the red cell, and the same cell distribution curve, which are to be found in pernicious anaemia (1922)

Although Oxyuris vermicularis occurs very frequently in children, material from which to study the early development, mature female worms, was difficult to obtain.

Specimens were found both in the normal stool and in the stool after treatment with santonin. Egg-laying began as soon as the worms came into contact with air; those which happened to be on the surface very quickly became surrounded by a white deposit of eggs and the worms themselves became reduced to fine threads, which were difficult to detect: Egg-laying was also induced by bringing females into water at body temperature.

Towards the end of 1923 the results of some feeding experiments of mice with gravid segments of Hymenolepis fraterna Stiles and Hymenolepis longior Baylis were described (Jl. Helminthology, Vol. 1, pp. 195–196). Intravillous cysticercoids were seen in animals killed on the fourth day after feeding and ova were passed by infected mice after an interval of 19 days.

The suggestion having been put forward that this did not prove direct development and that the results could be explained by the mice shedding their villi containing cysticercoids, contaminating their food and re-ingesting them, further experiments were undertaken in order to note the progress of development from day to day, and also to find out whether ingested cysticercoids survive and produce adult cestodes.

In the collection of nematodes assembled by Prof. R. T. Leiper in this department there are numerous examples of worms from game animals in different parts of the world. Amongst these the writer, in further study of the Œsophagostomes, has been privileged to examine bottles of some provisionally labelled Œsophagostomum, sp.? One lot was collected from the Roan antelope (Hippotragus equinus) by Dr. J. E. S. Old in Nyasaland, another was collected from the Wart Hog (Phacocærus æthiopicus) in Uganda by Prof. R. T. Leiper. The other bottle contained worms from the latter host collected in Northern Territory Gold Coast, by Dr. J. J. Simpson on two different occasions. A study of these specimens shows that they comprise three species new to science, and one species just recently described by Daubney (1924).

Being engaged on a complete revision of the genus Inermicapsifer Janicki (1910), we had occasion to examine some material from the Helminthological Department of the London School of Tropical Medicine. This material was kindly placed at our disposal by Prof. R. T. Leiper, F.R.S., to whom we here tender our sincerest thanks. We are also indebted to Prof. O. Fuhrmann for his useful advice and criticisms.

This parasite was described in 1910 by Railliet and Henry from material sent to them by Gaiger from India. Gaiger, in 1911, published a translation of the original description, together with some figures. In 1916, Gedoelst reported its occurrence in the Belgian Congo, but without adding to the description of the worm.

In 1839 Diesing described Stephanurus dentatus from the kidney of the pig. His description was incorrect in two important particulars, viz.— in stating that only one spicule was present and that the vulva was in the middle of the body instead of posteriorly. These errors, although corrected by Verril in 1870 and Louise Taylor in 1899, still persist, and it was on account of this that Drabble, in 1922, basing his diagnosis on a faulty text-book description, claimed that the Kidney worm of swine in New South Wales was generally distinct from Stephanurus dentatus. This worm he called Sclerostomum renium, n. sp.

This parasite was discovered in April, 1876, at Zagazig, Egypt, by Sonsino. He collected 35 specimens from the abdominal veins of oxen and sheep and from the portal vein of a bull. He stated that the parasite is larger than S. hæmatobium and has the same general aspect and characters, but is easily distinguished by the shape of the eggs. The eggs of S. bovis are .16 mm.-.18 mm. long and .04-.05 mm. broad, fusiform in shape and very much narrowed at the extremities. The pole which, in the oviduct, is turned away from the vulva, always carries a pyriform spine.

Intestinal infections with parasitic worms are wide-spread in the Tropics. It is estimated that half the population of the World is infected with hookworms. Infection is propagated by contamination of the soil with the bowel discharges which contain the eggs of these parasites and prevention depends upon the adoption of a system of sewage carriage which ensures the safe disposal of the distribution of these eggs. The various methods of sewage disposal now operating in British Guiana and elsewhere in the tropics are adaptations, with few or no alterations, of schemes originally introduced to meet conditions prevailing in temperate climates. Prior to the visit of the Filariasis Commission of the London School of Tropical Medicine to British Guiana in 1921 the fate of the eggs of the hookworm and of other parasites in the system has not been scientifically studied.

As there is no complete or adequate description of this parasite of dogs and foxes, and as it is proving to be of considerable importance in the newly established fox-breeding industry, it was thought advisable to prepare an account of its morphology. The material from which this description was made was obtained from a British fox which died at the Zoological Gardens, London, in June, 1923.