The protozoa found in the intestines of termites constitute one of the most interesting but less illuminated fields in protozoology. The amount of work done by a number of authors in several different parts of the world is, however, already fairly large, especially valuable papers having appeared in recent years, so that some light has been thrown on the field. Nevertheless, important questions regarding morphology, physiology, systematics, etc., still remain either insufficiently studied or almost untouched. Having myself been occupied for some years past with these interesting organisms, harboured by three species of termites in Japan proper and Formosa, and having made observations which seem to be of some interest, I propose in this paper to describe the chief results of my studies.

As stated in a slip inserted opposite the first portrait-plate of this series, the collection herein presented is issued without regard to chronological order, moreover, the portraits are confined to those men of science who, in various ways, have advanced the subject of parasitology.

In my previous paper (Parasitology, XI. 1919) on the life history of a Calliphorine fly, Melinda cognata Meig., the larvae of which live as parasites in a snail (Helicella virgata), I gave a complete account of all the Dipterous larvae feeding upon molluscs.

A Re-Examination of the type-specimens of “Sclerostoma” clathratum Baird from the African elephant, which are in the British Museum, has led to a rather interesting discovery. The material was contained in two bottles, labelled in Baird's own handwriting. One bore the name “Sclerostoma clathratum Baird,” and contained a single male specimen of the form now known as Grammocephalus clathratus. The other bottle was labelled “Sclerostoma clathratum Baird, ♀,” and proved to contain worms of both sexes and of quite a different type from Grammocephalus.

In Pediculus humanus are found two groups of excretory-accumulatory cells known as nephrocytes.

The one group, the peri-oesophageal, lies ventrally and consists of large cells aggregated usually in two masses about the oesophagus anterior to the reniform salivary glands.

The second group lies dorsally and consists of disseminated cell aggregates linked with the fat body.

The typical nephrocyte is a binucleate cell with granular protoplasm containing greenish droplets of varying size. The excretory function of the nephrocytes is demonstrated by intra-coelomic injection of ammonia-carmine. The latter, 24 hours after injection, is taken up by the nephrocytes which become red and filled with the carmine granules. These granules remain in the protoplasm of the nephrocytes throughout the life of the insect.

Similar cells exist in Mallophaga and have been wrongly described by some authors as salivary glands.

The two groups of nephrocytes, described by us in Pediculus, occur in other insects, but the dorsal group in the latter forms usually two chains of cells (known as pericardial cells) lying on either side of the heart.

Woodcock (1910) discovered a trypanosome naturally occurring in the blood of British sheep. This finding was confirmed by Behn (1911, 1912) in Germany. In both cases the authors did not give any description of the parasite, which was seen by them only in single cases, and they failed to cultivate the trypanosomes.

Few people have any conception of the rapid growth and the importance of the new industry of raising black and silver foxes for their fur. According to Dearborn, 1917, the first profitable fox ranch was established in the Canadian Province of Prince Edward Island in 1894. This ranch, the forerunner of a remarkable industry, was stocked with two pairs of silver foxes, a rare and beautiful colour phase of the common red fox found in nearly all of the United States and Canada.