This subject has already been considered in some of its aspects in the first part of this paper, but the methods which apply more especially to the study of the internal anatomy will now be dealt with.

Agrippina bona, a gregarine parasitic in the gut of the larva of the rat-flea Ceratophyllus fasciatus, was first described by Strickland in 1912. His account of the sporulation of the gregarine was so curious that a more detailed investigation has been undertaken, which has given rise to the present paper. The work has been done in the Quick Laboratory, under Professor Nuttall, to whom I wish to express my thanks for the interest he has taken in my researches, and for his constant encouragement.

The virus of rinderpest is present in the blood and all the body-fluids during the febrile period. In the blood it is so plentiful that the inoculation of a single drop of a 1 in 10,000 dilution is said to be sufficient to infect a calf. According to Nicolle and Adil Bey the causal agent is filterable, and therefore is supposed to be ultra-microscopic. Direct examination of fresh specimens reveals nothing parasitic, nor has anything of the kind been shown by various methods of staining of dried films.

This brief note is the result of a series of examinations of blood-films of various mammals and was suggested by Dr Braddon's interesting paper, the manuscript of which I had an opportunity of reading while working in the Quick Laboratory, Cambridge1.

Among other cestodes collected by me some years ago were specimens of the prismatic malformation of a tape-worm which I have recently examined. This abnormality in the taenioid group of cestodes has been frequently reported in Europe, especially in Taenia saginata, since Andry's case was first described in 1700. This malformation is known as Taenia ‘tridre,’ ‘triquestre,’ or ‘prismatique’ in French; as ‘dreikantige’ in German, and as ‘tri-radiate’ or ‘prismatic’ in English. But as far as my knowledge goes, we do not find a full description of any such abnormality in Taenia crassicollis, though a brief description of it was given by Bremser in 1819 and 1824. It is now recorded for the first time from Japan.

“Tick paralysis” occurs in British Columbia and affects man, sheep, and probably other animals. The disease is caused by the bites of Dermacentor venustus Banks. It is usually of short duration, is benign in character, but occasionally it persists for long periods, and may terminate fatally. From an economic point of view, the disease is of some importance to the sheep industry. The causative agent has not been discovered, and the disease has not been reproduced by inoculation. The most likely hypothesis is that the tick injects a toxin which gives rise to symptoms appearing coincidentally with the complete engorgement of the tick. In three consecutive cases, experimentally produced by me in lambs, paralysis occurred six to seven days after the ticks were put on. In no case did I fail to produce paralysis through the agency of the tick bites. It has been proved that D. venustus usually bites sheep along the back-bone; possibly the point of attachment may have some bearing on the symptoms or severity of the case. It is probable that other species of ticks may produce a similar disease. No larvae or nymphs were encountered on sheep, and I have no records of their attacking man in British Columbia.

The following note is published by way of supplement to the foregoing paper on “Tick Paralysis” by Hadwen, as it records a positive experiment carried out in Cambridge upon a dog experimentally infested with Dermacentor venustus obtained from Canada.

The diseases included under the general term of piroplasmosis are amongst the most devastating which affect domesticated animals, and they are, consequently, of great economic importance. As far as known, all forms of piroplasmosis are tick-transmitted.