While fixing a number of tapeworms (Anoplocephala perfoliata Goeze) from the small intestine of the horse, I came across a small tri-radiate specimen. This abnormality has previously been described by Neumann (2), but only briefly, and without any account of the internal anatomy. It therefore seemed advisable to compile a short account of the most salient characteristics. For the material I am indebted to Dr C. L. Boulenger, Helminthologist of this Department. I have also to thank Professor L. G. Neumann for obtaining for me a copy of his paper.

My interest having been aroused in Calliobdella lophii, I requested all my friends engaged upon the sea to keep a look-out for any leeches that might come to hand and especially for Calliobdella. Accordingly on 6. VIII. 1914 I received a specimen of a leech, taken near St Margaret's Hope towards the north-east of S. Ronaldsay in the Isles of Orkney, which as far as I can discover has never been described before, and which presents peculiar and interesting features not wholly dissimilar from those of Calliobdella. I propose to name the leech Ganymedes (or, if this name should be pre-occupied, Ganymedebdella) cratere.

1. The eggs of Nematodirus filicollis when laid contain an embryo with seven or eight cells, they pass out of the infested host with the faeces.

2. Even under favourable conditions development takes place slowly and the embryos are not ready to hatch until 24–28 days have elapsed. In their early stages the embryos are not able to withstand desiccation and are killed if frozen or subjected to high temperatures.

3. Whilst still within the egg-shell the embryo undergoes two ecdyses and when ready to hatch is enclosed in a tightly fitting sheath formed by the incompletely cast skin of the second moult; the larvae on liberation from the egg-shell are therefore in a more advanced condition than those of most other Strongylids (e.g. Haemonchus or Anchylostoma) and are in a stage comparable with that reached by the latter at the end of their period of free existence.

4. The sheathed larvae are often retained for a long time within the egg-shells and both in this position and after hatching can resist complete desiccation for considerable periods (twenty months or even longer); when dried they are able to withstand freezing as well as temperatures much above those likely to be met with in the open.

5. The free larvae will live for a considerable time in water, they possess well-developed migratory instincts and climb vertical surfaces, such as grass stems and blades, and the glass walls of the vessels in which they are kept.

6. The sheaths are cast off by the larvae when these are subjected to temperatures approximating to the blood-temperature of the host; completion of the second moult occasionally also takes place at laboratory temperatures under certain abnormal conditions.

7. No infection experiments were made on sheep, but other evidence shows that these animals must become infected by swallowing the sheathed larvae, either when free or whilst still enclosed in the eggshells.

8. A number of young stages of the parasite were met with in the intestines of sheep, the smallest of these being only little more advanced in structure than the larvae just after ecdysis.

Two species of the genus Stephanochasmus have been found in the fishes examined for parasites at the station of the Carnegie Institution of Washington, situated on the island of Tortugas in the Gulf of Mexico. These are S. casus Linton and S. sentus Linton. The anatomy of these worms contains several novel and interesting features, and that of the first named will be described here in detail.

The present paper contains the results, other than those already published, of work done in the Department of Agricultural Zoology at the Birmingham University upon the tapeworms of birds. At the commencement, a little over two years ago, the aim was to make a complete investigation of the Cestodes of British birds, both from the standpoint of anatomy and also of life-history, since, as far as I am aware, there exists no adequate description of them. It was found impossible to obtain a regular supply of any one species of tapeworm, hence the work upon one particular species could only be carried on spasmodically. The results, having to wait upon the occurrence of the material, are necessarily incomplete. Circumstances having made it necessary temporarily to postpone the work, it was considered advisable to write up and publish the results so far obtained.

Variability in the size and, in a lesser degree, the taxonomic features of male ticks, has arrested the attention of all who have had occasion to examine moderately large numbers of examples of the same species. In the case of the female tick, this variability, though doubtless coextensive with that of the male, is more or less obscured by the wide range of variation in size, depending upon the degree of engorgement; and, also, by the fact that in the female tick the taxonomic characters are, as a rule, less pronounced. The present note is only concerned with variability in the size of the male.

This paper is written with the purpose of drawing further attention to the value of the complement fixation reaction as a diagnostic test in dourine and of recommending a method of procedure and technique arrived at with an experience of 15,000 tests for dourine made at the Veterinary Research Laboratory, Lethbridge.

The incidence of Helminthiasis at Mombasa is herein briefly dealt with chiefly in tabular form. The tables give the result of the first 100 examinations conducted on natives of indigenous races complaining of intestinal troubles, admitted into or attending hospital.

(1) There is very little, if any, abnormal destruction of erythrocytes in cases' of infection with East Coast Fever. This is proved by blood counts, haemoglobin estimations, and the condition of the bloodforming and blood-destroying organs, all remaining practically normal. This is in marked contrast to what obtains in piroplasmosis.

(2) The hypothesis advanced by Nuttall fits all the facts. According to this hypothesis the invasion of the corpuscles occurs in the internal organs where the parasites develop, and the corpuscles only act as carriers of the parasites in the blood, thereby conveying them to the tick which serves as the vector.

(3) Since few, if any, of the corpuscles are destroyed they rapidly become charged with an increasing number of parasites which are being continuously produced in the internal organs as evidenced by Koch's blue bodies which form and break up in the lymphatic glands, spleen, liver, bone-marrow, etc. (Gonder, Nuttall).

(4) There is a marked leucopenia in East Coast Fever, the polymorphs decreasing less rapidly than the other elements. This is in contrast with the leucocytosis observable in piroplasmosis.

Eight forms, referred to the genus Ascaris, were described by Dr W. Baird between 1853 and 1868, all of which are represented by type-specimens in the British Museum collection. Stossich, in his monograph of the genus Ascaris (1896), mentions six of them, but all these are regarded by him as species inquirendae. Baird's descriptions are in all cases brief, and confined almost entirely to external features, this rendering them inadequate for the requirements of present-day systematic workers. I have, therefore, thought it advisable to undertake a revision of the various types, with a view to deciding more definitely their systematic value, and, where possible, to re-describe those which appeared to me to represent valid species.

During an investigation extending over several years of the forms of Trypanosoma lewisi, as met with in naturally infected Mus decumanus, I have met with many phases which I have not seen described.

During the past summer numerous inquiries were received by Professor Elford, Dominion Poultry Husbandman, Experimental Farm, Ottawa, with regard to an apparently infectious disease appearing among ducks. So frequent and insistent were the appeals for aid in this connection that the co-operation of the Health of Animals Branch was requested. This resulted in an investigation being undertaken to ascertain the clinical nature of the disease; to demonstrate, if possible, the cause; and also institute measures for its prevention.

Consideration of the outbreak of fever at Morib in Selangor, Federated Malay States, impresses us with the great practical importance of obtaining an exact comparative infectivity table of the various anophelines, compiled on a comprehensive basis; it is only by accurate study of a disease and the factors responsible for it, that it can be successfully combated.

At Morib we can only rely on general considerations and conclude that the species ludlowi has been causing most of the trouble.

It would seem that the reason that hill-land malaria in Malaya, and perhaps India, is so difficult to get, rid of is because it is conveyed by mosquitoes of high infectivity and low prevalence, whereas low-land malaria can be easily allayed because it is conveyed by mosquitoes of low infectivity and high prevalence. It is a corollary to this that if malaria in any community can be easily allayed, it is caused by mosquitoes which possess low infectivity.

During the past year a considerable number of fishes has been forwarded to the Institute for examination. The great majority have been marine fishes obtained from Cleveland Bay, or from the reefs off Magnetic Island, but a few fresh-water fishes from local creeks have also been included.

That ticks are a very serious trouble in countries where stock forms the basis of the wealth of the country is too well known to require elaborate demonstration, for the fact that they are the agents of transmission of some of the most fatal and devastating diseases is now generally recognised by the stock-farmer.

Since the appearance in 1901 of Looss' important monograph on the Sclerostomes of Horses and Donkeys in Egypt a much greater interest has been shown in the presence of these and allied Nematodes in other parts of the world, but, although nearly fifteen years have elapsed since that publication, very little addition has been made to our knowledge of this branch of helminthology

A fertile source of error in protozoology is to be found in the overlooking of the occurrence of mixed infections in a host. Two organisms, each independent of the other, may happen to coexist in the intestine of an insect or the blood of a vertebrate, the result being that the investigator may confuse stages in the life-cycles of parasites which are not related to each other. This source of error has led to unwarranted generalisations which have impeded scientific progress for years. Two examples at once come to mind—the trouble wrought by Schaudinn in 1904 in confusing the life-cycles of the protozoa found in the little owl, and the impediment put in the way of progress by the omission of certain workers to recognise that Crithidia grayi was not a part of the life-cycle of a trypanosome. The existence of mixed infections was overlooked in each case.

All of our guinea-pigs infected with Trypanosoma brucei (strain “ferox”) died whether they were treated or not. It is evident that both tryposafrol and novo-tryposafrol exerted a directly injurious effect upon the guinea-pigs. Reckoning the day on which the guinea-pigs were inoculated as day 1, the 19 treated guinea-pigs died respectively on days 5, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 11, 18, 19, 19, 26, 27 and 33. The six untreated guinea-pigs died respectively on days 23, 25, 25, 27, 44 and 45. The two preparations of the dye are therefore worse than useless as remedies for Nagana in guinea-pigs.

Five dogs were infected with Piroplasma canis (Cambridge strain) of which four were treated and one not treated with novo-tryposafrol.

All of the dogs died although treatment was given under the most favourable conditions, starting on the day of inoculation. The four treated dogs died on days 12, 9, 17 and 12 after inoculation respectively; the untreated (control) dog died on the 13th day. The drug exerted no influence upon the course of the disease, nor upon the appearance of the parasites and their progressive increase in the blood. Novo-tryposafrol may therefore be regarded as useless in the treatment of canine piroplasmosis, and, judged from these results on dogs, it will no doubt prove to be equally useless in the treatment of bovine piroplasmosis when it has received a scientific trial in competent hands.

In view of the negative results obtained by ourselves and other independent investigators, working especially with trypanosomiasis, we conclude that the value of tryposafrol or novo-tryposafrol as a remedy for any of the diseases enumerated by the authors is open to grave doubt since the chief claims as to its efficacy were based on experimental results which the authors state that they obtained with Nagana.

In the course of dissecting a parakeet (Brotogerys tirica) sent to me for examination, I came across several large tapeworms of the genus Cotugnia in the duodenum. They did not agree with any of the species previously described and, upon closer examination, showed so many points of difference as to justify the creation of a new species for them. I propose the name Cotugnia brotogerys for this species.

Within the last few years several books and numerous papers have been published dealing with various problems relating to the life-histories, and disease-spreading capacities, of house-frequenting and other nonbiting flies. An intimate knowledge of the habits of flies is essential if the most suitable methods are to be devised in order to diminish their numbers, yet it is only too evident that many of the accepted hypotheses are founded on the most superficial observations, and that extensive and carefully planned experiments, with a few notable exceptions, are conspicuously absent.