Since November 1906 I have had in the animal house attached to the Bacteriological Laboratory, a rather large female Macacus pileatus (No. 47). This monkey, which had been bought from a villager, had never been used for any experiment: it was kept in the same cage with a monkey inoculated with yas. In October 1907 the monkey, which so for had been in good health, began to lose appetite, and looked somewhat ill: nevertheless the animal continued to jump about in the cage and play with its compantion till a short time before death, on 5. xi. 07. The monkey never had any diarrhoea, and I thought it might have died from a peculiar form of malaria, extremely common in Ceylon monkeys.

The muscles of the head. In the preceding part of this paper (Journ. of hyg., 1907, p. 297) some account was given of the muscles of the pharynx and there remain to be considered the rest of the muscles of the head.

In stained preparations Piroplasma canis, P. bovis and P. pitheci may be distinguished from other intracorpuscular parasites by the presence of intracorpuscular pyriform bodies, usually occurring in pairs and less commonly in fours, eights and sixteens. These pyriform bodies show a dense mass of chromatin near the pointed end and a loose mass, often connected with the dense mass, situated towards the blunt end. In suitable preparations peculiar dividing forms, most typically repre-sented by trilobed forms or more or less pyriform bodies joined to a single smaller rounded or elongated mass of protoplasm, may be seen.

A popular belief prevails in Russia that the bug Acanthia lectularia plays a part in the spread of relapsing fever. Flügge (1891) however appears to have been the first scientific writer to suppose that vermin might spread the disease. This view was also held by Tictin (1897) who considered that man may become infected by (a) being bitten by bugs which had previously fed on blood containing Spirochaeta obermeieri, or (b) by his crushing such bugs and infecting himself with the spirochaetes through lesions in the skin induced by scratching. Tictin injected the gut-contents of infected bugs which had recently fed on a relapsing fever patient into monkeys and infected them. When the bugs were crushed 48 hours after feeding on infected blood their contents did not produce the disease in monkeys.

The importance of various species of ticks in relation to the propagation of protozoal diseases, is so generally recognised that it has appeared to us eminently desirable to make a detailed study of one of the common species. Such a study has seemed to us specially necessary for the reason that our knowledge of these parasites is very imperfect, in spite of the fact that they possess an economic interest of the first order. Some of the diseases which ticks transmit, notably those due to the haematozoal parasites belonging to the genus Piroplasma, are among the most devastating affections of domesticated animals in many parts of the world, the useful animals which suffer from piroplas-mosis being cattle, sheep, goats, horses, and dogs. The disease known as “Heart-water,” occurring in South Africa and affecting sheep, goats and cattle, is likewise tick-transmitted. A disease of the domesticated fowl, analogous to relapsing fever in man, likewise of economic importance and occurring in different parts of the world, has also been demonstrated to be transmitted from animal to animal through the agency of ticks. The fowl disease is due to a Spirochaeta which is conveyed by ticks; the same holds for human “tick fever” and a spirochaete infection in cattle occurring in parts of Africa. Recent investigation appears to have clearly established the fact that a tick conveys spotted or Rocky Mountain Fever to man. Moreover it has been claimed that a Nematode worm, the Filaria perstans, parasitic in man, undergoes its development in a tick which is capable of conveying the parasite from one human host to another. There can be no doubt but that ticks will be found, upon further investigation, to be associated in the transmission of an increasing number of diseases in animals.

Leeches are common in the fountains and pools of Palestine, particularly in the northern parts, known to us familiarly as ‘Galilee,’ and further north in the district of the Lebanon. In the later summer and autumn months they are so plentiful in places that almost every horse and mule passing through these parts has a bleeding mouth. Under such conditions it is not wonderful that human beings from time to time are attacked. The domestic supplies of water are usually protected by the water-carrier's custom of straining it through a piece of fine muslin as he or she fills the pitcher. In some parts of the land the water at the source is kept free from leeches by means of fish; at Deishun, for example, a village in ‘Upper Galilee’ inhabited by Algerian settlers, the large stone tank into which the spring runs is full of a special fish—Capoëta fratercula, a kind of carp—which is there bred for the purpose and which is treasured by the inhabitants with superstitious reverence. Many of the springs in the mountains of Galilee and in the Lebanon are widely known for the multitude of leeches which lurk in their waters, but a thirsty traveller seldom has self-control enough to restrain himself from drinking, and when he does so, particularly at dusk or in the night, he is very likely to suck one in. It is stated in Allbutt and Rolleston's System of Medicine (2nd ed. Vol. II. Part II. p. 959) that the leech “remains in the stomach for a time and then begins to wander.” I have had a long experience of leeches as human parasites but have never seen nor heard of a case like this. The leech in every case I have met has attached itself to the mouth, throat, etc. in the process of swallowing, and I am convinced that once the leech reaches the stomach it is killed. I have never heard of any after symptoms from cases where to my knowledge a leech has been completely swallowed. Many patients can describe the actual moment (during deglutition) when the leech seizes on the throat. One would suppose from the great frequency of leeches in the mouths of horses, etc., that they must sometimes find a temporary resting place there in the human subject; such cases do not however come into the hands of a medical man—the patient or his friends readily removes such an intruder. In the cases, some three dozen or so, which I have had under my own observation the leech has been attached to the epiglottis, the pharynx, the nasal cavities, or—most common of all—the larynx. The frequency of the last situation in my clinical experience is doubtless due to the inability of the fellahin to do anything themselves for the relief of such cases.

I owe to Prof. G. H. F. Nuttall and Mr A. E. Shipley the opportunity of examining three specimens of a West African leech sent by Dr C. Wellman from Benguella, Angola. They were described as land leeches ‘taken four or five miles from any water’ and were preserved in alcohol. A brown, vermiform object protruded from the mouth of the largest specimen.

some hundred and ten years ago, Dr Gotthelf Fischer, in a communication dated from Vienna, described a Nematode living in the swim-bladder of the trout. He named this worm Cystidicola farionis and his description is accompanied by some rough cuts. Bosc (1802) re-described the same Nematode under the name Fissula farionis. The same worm was again described by Rudolphi (1819) under the name Spiroptera cystidicola. Dujardin (1845) mentions it under the name Dispharagus cystidicola. Later it was removed by Schneider (1860) from the genus Spiroptera and placed in Diesing's genus Ancyracanthus. von Linstow uses this generic name “with a difference”; he spells it Ancryacanthus.

The nematode worms discovered by Mr Shipley in the swim-bladder of Trout belong to the species Cystidicola farionis, first described by Fischer, and considered by him to represent a new and distinct type in nematode structure for which he proposed the generic name Cystidicola. Later writers refused to accept the new genus and included it in various other groups (see Synonymy, p. 190). In accordance with an old nomenclatural practice the proposed generic name was adopted as the specific name in place of that originally given, thus Cystidicola farionis became, for Rudolphi, Spiroptera cystidicola. From a detailed examination of the various characters of C. farionis I have come to the conclusion that Fischer was correct in creating a new genus for the new forms, and I therefore propose the reinstatement of the abandoned name Cystidicola. It is also in accordance with modern nomenclatural ruling that the original specific name farionis should be adopted in place of cystidicola.

p. 48, second line from the bottom,

instead of “C. W. Andrews” read “Dr H. E. Durham.”