The identification of species of Rhipicephalus is likely to give more trouble than is the case with any other genus of Ixodidae, for while, on the one hand, there are few species which depart greatly from the general type, on the other hand the range of variation within the species is extremely great. In no genus is it so dangerous to describe a new species from a single individual, especially if the specimen be a female.

Since 1906 trypanosomes have been found in ten species of mammals by officers of the Health of Animals Branch.

I propose in this paper reviewing very briefly the work which has been done on the Ceylon pearl-inducing worm, during the last ten years. This is particularly appropriate at the present time as the Pearl Banks—which have been under lease to a London Syndicate, who have spared no pains or money in the investigation—may at an early date revert back to the Government. It remains to be seen to what extent the Ceylon Government will profit by these investigations, and whether they will continue the work with the vigour which has characterised the Company's administration.

In the last issue of Parasitology a description is given by Wenyon (5) of the developmental cycle of Leucocytozoon canis in the tick Rhipicephalus sanguineus. Wenyon refers to the description of the development given by me (2), but rightly points out that one stage, that of the large compound cysts, was overlooked. The surmise, however, that these large and easily ruptured cysts were overlooked owing to their having been broken up in the preparation of films is only part of the truth. A full explanation involves facts in regard to the development of this parasite which have not been touched upon by Wenyon; it is possible, as will be seen shortly, that Wenyon's description of the cycle, like mine, involved a considerable error. In this respect, as a result of work not yet published, I am able to supplement what has been written on the subject.

Die unter diesem Titel in Vol. iv, No. 4 dieser Zeitschrift erschienene Arbeit V. Huffman's gibt mir Anlaß zu folgenden Bemerkungen, nicht weil ich ihre Ansichten nicht teilte, sondern weil sie geeignet ist, über meine Stellung zu der Frage der Kurloff-Körper einen unrichtigen Eindruck zu erwecken. Im ersten Absatz der Arbeit steht der Satz: “Therefore it is not with surprise that we find Ferrata, Patella, Goldhorn and Schilling and others believing these bodies to be protozoan in nature. Patella however is the only one who claims to have observed a flagellate develop from a Kurloff-body and of course this observation would put an end to all dispute if it could be verified.” Die Arbeit wendet sich indessen nur gegen die Patella'schen Anschauungen, obgleich im Literaturverzeichnis meine Arbeit über die Aehnlichkeit dieser Einschlüsse mit Chlamydozoenkörpern zitiert ist. Die gegen Patella angeführten Beweisgründe decken sich im wesentlichen mit den meinigen (abgesehen von durchaus negativen Flagellatenuntersuchungen, deren Zugehörigkeit von vornherein sehr unwahrscheinlich war), sind aber gerade im morphologischen Teile weit weniger eingehend und führen zu dem gleichen Ergebnis, daβ die Kurloff-Körper sicher keine gewöhnlichen Protozoen sind. Statt aber meine ihm bekannten Resultate zu bestätigen, erwähnt der Autor mich kurz unter den Anhängern der Protozoennatur der Kurloff-Körper. Mit der von mir betonten Aehnlichkeit mit Chlamydozoenkörpern ist keineswegs gesagt, daß sie wie diese noch ziemlich zweifelhaften Gebilde nun wirklich Erzeugnisse einer Infektion (höchstens mit ultravisiblen Erregern) sein müßten; ich habe ausdrücklich ausgesprochen, daß das, was von den Kurloff-Körpern dargestellt wird, eine Reaktionsstruktur der Zelle selbst vielleicht ihres Kerns auf eine unbekannte Ursache zu sein scheint.

The following descriptions relate to a new species of Amblyomma in all its stages, to two species of Haemaphysalis of which diagnoses of the males and females are given, and to the hitherto unknown larva of Ixodes putus:

In a paper published in April, 1910, I described and figured a new intracorpuscular parasite found in smears made from the spleen and liver of a jackal (Canis adustus), the animal having been shot by Mr W. F. Cooper in British East Africa. As I stated at the time, I hesitated about referring the parasite to the genus Piroplasma, and only did so provisionally because it offered a resemblance to two parasites found in the internal organs of one of my dogs which had “recovered” from P. canis infection. I, however, added: “Should future investigation prove that the parasite of the jackal differs from the types of P. canis encountered in ‘salted dogs’ I would propose to refer it to a new genus, Rossiella (Rossia being preoccupied) in view of its specific name.”

“Piroplasmosis,” or “biliary fever” in horses, has hitherto been regarded as a disease due to a distinctive parasite, Piroplasma equi Laveran. We propose to show that there are two specifically distinct parasites concerned in the production of biliary fever, and that consequently two distinct diseases have hitherto been confused under this name and under the name of piroplasmosis.