The material which forms the basis of the following account consists of two tubes of tapeworms collected from ostriches at the Veterinary Pathological Laboratory, Nairobi, British East Africa. One tube contained approximately 12 scolices and the anterior portions of the strobilae attached to them, together with several fragments of the more posterior portions: these are described under the name Davainea beddardi n. sp. The other tube contained one large fragment of a Davainea and several smaller pieces but no scolices: these are described under the heading Davainea sp. For this material I am indebted to Professor G. H. F. Nuttall, F.R.S. to whom I wish here to express my thanks. I have also to acknowledge my indebtedness to the Librarian of the Royal College of Veterinary Surgeons for allowing me to consult literature unobtainable elsewhere.

In the paper on the association of Rickettsia with Trench Fever, by Arkwright, Bacot and Duncan (1919) mention is made of a bacillary infection of the excreta and guts of lice (Pediculus humcmus). A Gram-negative cocco-bacillus was isolated in pure culture. It was non-motile, fermented glucose, mannite and lactose very slowly, and formed acid and clot in milk in about 14 days.

The forms under consideration resemble Rickettsia prowazeki—the supposed cause of typhus fever—which occurs in lice that have fed on typhus fever patients.

Since the publication of Part IV (Stewart, 1919), four papers dealing with the life-history of Ascaris lumbricoides have appeared.

(1) Ransom and Foster (1920) give a full account of their work, preliminary reports of which have already been published (1917 and 1919).

As evidence in the problem of whether the worm can undergo full development in one host alone, they attach great importance to two experiments, one on a kid and one on a lamb, in which after the administration of ripe eggs of A. suilla, they recovered worms from the intestines. In the kid, which died 24 days after the first feeding, the worms measured from 4·3 to 11·4 mm.; in the lamb, which was killed 103 days after feeding, the worms measured from 60 to 110 mm. The authors consider that, as Ascaris infection is uncommon in goats and sheep, the worms may without doubt be ascribed to the experimental feeding. They record five experiments on pigs which gave doubtful results, since the pigs fed with Ascaris eggs were found, after varying periods, to be on the average less infected with Ascaris than pigs which were kept as controls, and had not been so fed.

1. The specimens in the material here dealt with make a series of forms connecting F. angusta (Railliet) and F. aegyptiaca (Looss).

2. No important character separates any of these flukes from F. gigantica (Cobbold) and they must accordingly be all identified with this species.

3. The following key represents the simplest method of distinguishing between the species of Fasciola at present described. (For detailed diagnoses see the literature referred to below and this paper.)

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.

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.