From the researches of Onchi and Nishio it is known that the encysted larva of Heterophyes nocens Onchi et Nishio is found in the Japanese mullet. H. nocens is closely allied to H. heterophyes v. Siebold, which is found commonly in. man, dog and cat in Egypt. It may be assumed that the larva of the Egyptian Heterophyes will be found likewise in certain fishes allied to the mullet. On the homeward voyage from my tour in Europe I examined some specimens of mullet in Port Said, for the purpose of finding the young larva in them, and was fortunate enough to discover encysted larva. I carried back with me some of these fishes fixed by formalin. After returning to Chosen (Korea) I examined the parasite, and found that it certainly belongs to a species of Heterophyes. Its morphological description is given in the present short communication.

1. The paper deals with nematodes of the genus Aphelenchus causing diseases in cultivated plants. A list of these, with the main pathological conditions to which they give rise, is set out on page 144.

2. Each parasite and the disease due to it is dealt with, and particulars are given concerning the structure of the worm, together with the symptoms and biology in each case.

3. A general discussion on the problem of the appropriate treatment of these diseases is given, and the suggestion is made that some form of heat treatment of infective soils is likely to give the best results, owing to the fact that comparatively low temperatures are lethal to the parasites.

The breeding and raising of small mammals, such as skunk, minx and fox, for their fur, is a comparatively young industry in Britain, and one of the most serious hindrances to the successful husbandry of these animals is the occurrence, at any rate, in the skunk, of certain helminth parasites. We have been investigating the worms sent to us from a skunk farm, where the stock is very extensively infected, and where serious injury to the animals and great deterioration of the coat is attributed to these parasites.

Nicoll and Minchin gave an account in 1910, in the Abstract of Proceedings of the Zoological Society of London, of their finding a Cysticercoid in the rat-flea, Ceratophyllus fasciatus, “very like the scolex of Hymenolepis murina Duj. … it [H. murina] was the only rat-tapeworm to which the Cysticercoid could be referred.”

During the past few years the writer has had an opportunity of making observations on the quiescent larvæ of Tylenchus tritici occurring in galls from ears of wheat, and of examining certain resting stages of Tylenchus dipsaci from diseased Narcissus bulbs.

In 1865 Leuckart described from the Cat, in Germany, a very minute Strongyle worm which he called Ollulanus tricuspis. This worm which was recorded from Britain by Cobbold (1873) and Stirling (1877), but was not properly described or figured, has occurred recently in some cats examined by the writer.

In December, 1922, Sir John Russell called the writer's attention to some diseased potatoes which had been sent to the Rothamsted Experimental Station. Dr. W. B. Brierley, Head of the Mycology Laboratory, had examined them and had failed to find evidence of fungal attack though the diseased areas bore a superficial resemblance to the appearances presented by “blight” affected potatoes due to Phytophthora infestans. He had, however, found numerous eelworms in the diseased tissues and because of this the writer was asked to examine the material.

1. From an examination of over 700 sheep of Scottish origin a list of the parasites found in the intestinal tract has been prepared.

2. The commonest parasite found is Monodontus trigonocephalus, a worm which occurs also in goats and cattle. This parasite can be found at any season.

3. Nematodirus sp. also is extremely common during the warmer months.

4. From a systematic geographical examination of sheep it has been ascertained that Monodontus trigonocephalus occurs in every district in Scotland ; and of 40 sheep examined in this part of the enquiry, 38 were found to be infected. Thirty specimens have been recovered from an apparently healthy sheep, but usually the number is much smaller (7–10).

The earliest record of a mammalian lung fluke was made by Diesing in 1850, who described Distomum rude from the lungs of Lutra brasiliense, from Brazil. This species was transferred to the genus Paragonimus by Stiles and Hassall in 1900.

Since Looss described in detail the anatomy and histology of the type species of the family Ancylostomida no attempt has been made to study comparatively any of the other genera of this group.

From its economic importance as a little-known, though frequent, parasite of ruminants and its scientific importance as type species of the second sub-family of the AncylostomidcB, Monodontus trigonocephalus has been selected for description.

The biology of the infective larva of the Sheep Hook-worm Monodontus trigonocephalus would be expected on general grounds to resemble that of Ancylostoma duodenale, to which it is closely related. Two facts in the biology of the adults must, however, be borne in mind. In the first place, the normal temperature of man is about 37° C, while the normal temperature of the sheep is 39°–40° C. Secondly, both Looss (for A. duodenale) and Hesse (for M. trigonocephalus) have shown that the pre-infective larvæ feed actively on faecal matter. Looss has drawn attention to the fact that cultures of Ancylostomes made from the fæces of a host living on an exclusively herbivorous diet, were very much poorer in the resultant crop of larvae than those made from fæces of a host living on a partly carnivorous diet. Now the adult Monodontus lives in a host which is purely herbivorous, and the larvæ are reared in fæces entirely of a vegetable nature. One might therefore expect differences in the biology of the ensheathed stage.

The only account of the larval stages of Bunostomum trigonocephalum (Rud.) which I have been able to find is a brief note by Baillet (1866), in which he states that the larvæ of Uncinaria cernua Crep. = B. trigonocephalum (Rud.), develop in water and hatch within four or six days. The newly hatched larvæ are “rhabditiform,” .35 to .4 mm. long and ·23 to .3 mm. broad, and the tail is very thin and filiform.

Host: Cebus fatuellus. Habitat: Stomach. Locality : South America. Two males and two females were collected from the stomach of a Brown Capucin. The two males are respectively 37 and 41 mm. long by 1.5 and 1.65 mm. thick; the two females are respectively 54 and 60 mm.long by 2.9 and 2.75 mm. thick in their posterior third.

The occurrence of Ankylostomes resembling human hookworms in the domestic pig has been the subject of several recent papers, the most noteworthy being the contributions of Ackert and Payne (1922 and 1923) and Gordon (1922 and 1923).

During August, 1922, acting as an Honorary Parasitologist to the Zoological Society of London, I examined an Indian Cobra, the “Hamadryad” Naja bungarus, which died in the Society's gardens. A single trematode was found in the Gall bladder. It was living and active. A careful search for other examples of this trematode in the snake proved negative.

The nematode described in this paper was obtained from the minnow, Leuciscus phoxinus Linn. About 50 minnows were caught in Loch Lubnaig in Perthshire, Scotland. Only two specimens were infected, one with a single female, the other with two females and a male. The worms were found in the mucus of the posterior part of the intestine.

The following communication is based mainly on material collected at the Prosectorium of the Zoological Society of London. In it there is also incorporated a study of several species in the collection of the Helminthological Department of the London School of Tropical Medicine.

The Filariasis Commission, composed as it was of British, Chinese, and Mohammedan members, was able to take a more extensive and a more representative survey of the incidence of filariasis than would have been possible in the case of a single investigator. Dr. Khalil had frequent invitations to local Mohammedan ceremonies, and as these were usually held at night, he was able to examine a large number of bloodfilms from East Indian immigrants. Dr. C. U. Lee was very hospitably received by the Chinese families of Georgetown, and collected statistics as to the filarial rate amongst them on a scale that was hitherto unattainable. The whole commission, working together, was able to undertake a survey of an institution such as Georgetown Prison, the Almshouse, or Christchurch Public School with little inconvenience to the children or inmates. Thus from hospitals, schools, prisons, asylums, and domiciliary visitations, the Commission collected details and examined blood-films from 4,215 inhabitants of British Guiana. The total number of examinations was made up as follows:—

(1) The female can and does lay eggs.

(2) The eggs in the body of living worms do not develop beyond the 16-celled stage.

(3) The eggs passed in the fæces of chickens are in the same stage of development as those in the uteri of the adult.

(4) The eggs take about a week to develop and produce infective larva?, when cultured in well aerated water at a. temperature of about 25°C.

(5) The embryos undergo only one moult before reaching the infective stage.

(6) The second stage or infective larvae are generally ensheathed. They are non-climbers, do not penetrate the skin, and cannot resist dessication.

(7) In the body of the host the larvae soon reach the lungs, where they grow considerably in size and undergo two further moults.

(8) The final or fourth stage larvae are reached in about five days after infection.

(9) The larvae then copulate and migrate into the trachea where they attain sexual maturity in from 10 to 14 days later.

(10) The whole life cycle is completed within a month.