(1) An account is given of a serious infestation in sheep and lambs by Ixodes ricinus in the uplands of Denbighshire, North Wales.

(2) This infestation was accompanied by serious disturbance of health resulting in the general deterioration of the flock and the death of lambs.

(3) Experimental dippings were commenced in 1924, using a special “short-interval” arsenical dip supplied by the Cooper Technical Bureau, London. Serial dippings were made each spring at five-day intervals. When possible an early autumn series was conducted.

(4) The objects were (a) to control the infestation, (b) to control the diseased condition, and (c) to attempt to eradicate ticks from the land.

(5) The control of both the ticks and the disease were easily effected. A few sporadic cases of disease did occur during the course of the experiment.

(6) Eradication has not yet been accomplished, but the average number of ticks was reduced from 121 per animal in May 1924 to 0-96 per animal in July 1926.

(7) It is therefore suggested that short-interval dipping for serious tick infestation in sheep is practicable on British hill farms, and that resultant mortality from disease can thereby be reduced.

Having at our disposal material from various sources obtained from the intestines of monitor lizards, it appeared useful to prepare drawings and descriptions of the less known species of parasites.

Authors almost invariably figure the shell-gland of Cestodes in a form resembling that of a daisy's corolla. This may serve to indicate the position of the shell-gland but it should be remembered that the shell-glands are not all of this form. Thus, the shell-gland shown in Fig. 1 is somewhat shrub-like in form, consisting of irregularly fusiform elements which grow filamentous at one end and they are clustered on one side of the ootype of the uterine duct. The nucleus is situated in the fusiform portion and the filamentous portion extends toward the parenchyma of the cortical layer.

The purpose of this note is to record the occurrence of a haemogregarine parasite in the red blood corpuscles of the South American lung-fish, Lepidosiren paradoxa.

In a recent paper1, written jointly with Dr P. P. Laidlaw, methods were described for cultivating Entamoeba histolytica, and various other entozoic amoebae of man and monkeys, from the encysted forms. We there showed that cultures of all the species studied can be readily obtained by merely incubating such cysts in any of the media suitable for the cultivation of the corresponding active forms—provided that certain precautions are taken.

The present paper is the first of a series describing a collection of cestodes from the Biological Laboratory of the Egyptian Government School of Medicine, Cairo, the nematodes having previously been described in this Journal by Baylis (1923 a, 1923 b, 1923 c) and Boulenger (1926). The identification of this portion of the collection has presented great difficulties, the specimens, from long immersion in alcohol mixed with fragments of cork, having become so pigmented as to be virtually black and almost unstainable: but for a formula (soak for 3 to 5 days in pure beechwood creosote, then transfer for the same time to 5 per cent. hydrochloric acid in 70 per cent, alcohol) supplied by Dr H. A. Baylis—to whom the author tenders his most sincere thanks—the elucidation of their anatomy would have been impossible.

A mouse, which had been intraperitoneally injected with a filtered, diluted, cellular suspension of mouse-adeno-carcinoma, three months afterwards, was found to have developed a tumour of the same type on the pyloric end of the stomach surface, adherent to a cyst of the liver, containing the strobiloid larval stage of Taenia crassicollis.

Thirty-five other mice, similarly injected, but which were not infected with this cestode, did not develop growths in the peritoneum.

Dans le pus des ulcérations du gros intestin on trouve toujours en nombre plus ou moins considérable des macrophages d' un type spécial. On tencontre ces macrophages dans la dysenterie bacillaire, dans la dysenterie amibienne, dans le colitis ulverosa (cette dernière a, pour moi, une origine non infectieuse).

The monocystid here described was found in the coelom of Pheretima heterochaeta (Mich.).

The following account is based wholly on material fixed in vapour of osmic acid and methyl alcohol—other fixatives like Bouin's and Schaudinn's gave bad results.

The Trematode parasites of man have been so frequently listed and, for the most part, so fully described in various text-books and treatises on parasitology, pathology and tropical medicine that it might seem superfluous to enumerate them again. My object in doing so is to provide a basis for comparison with the parasites of the Primates, our knowledge of which is still extremely fragmentary, and with the parasites of Mammals in general. It is hoped that the works which are cited will prove to be the most useful or the most authoritative original references available.

In the Samoan Islands, in the South Pacific, one frequently sees horses and donkeys disfigured by large tumours. These occur on the pasterns and fetlocks, and occasionally between the eye and the nostril, but never on other parts of the body. They are often multiple, and they cause much inconvenience because of their size; many of them are larger than the animal's hoof (Plate XXIII).

Adult trematodes belonging to the genus LeucocMoridium Carus are here reported for the first time from North America. These flukes are intestinal parasites of birds and proved to be previously undescribed species.

In the present paper a key separating the species of the genus is given, and the following are described and figured as new species:

Leucochloridium certhiae n. sp. from Certhia familiaris americana;

Leucochloridium mniotiltae n. sp. from Mniotilta varia;

Leucochloridium icteri n. sp. from Icterus galbula;

Leucochloridium vireonis n. sp. from Vireo griseus griseus;

Leucochloridium sorae n. sp. from Porzana Carolina.