138 Piroplasma: Multiplication-forms 
on the study of stained specimens against the evidence derived from 
observations on living parasites. 
In the paper quoted we have shown that single parasites do 
undoubtedly divide by simple division (Diagram 28, p. 240) but in this 
case give rise to two amoeboid forms, each of which may proceed to the 
formation of pyriform bodies (Diagrams 30, 31 and 36, pp. 241, 242, 
262) in the manner we have described. 
Stained specimens of such preliminary divisions and apparent 
divisions (Diagram 29, p. 241) may have influenced Christophers in 
his conclusions. 
In stained preparations Piroplasma cards can be distinguished from 
other intracorpuscular blood parasites by the occurrence of intracorpus- 
cular pyriform bodies, which represent the mature form of the parasite 
in the blood. These pyriform bodies are most commonly present in the 
corpuscles in pairs, though multiples of two, four, eight and sixteen, are 
not uncommon. These forms generally show two chromatin masses, a 
dense and compact mass usually situated near the pointed end and a 
secondary mass of loose chromatin 1 which may be arranged in various 
ways, extending towards the blunt end. 
Dividing forms, fixed in the later stages of division, especially the 
trilobed forms which are of frequent occurrence in suitable films, are yet 
more characteristic. By a careful study of stained films we have been 
able to establish the fact that two other species of Piroplasma , P. bovis 
and P. pithed , divide in the same manner as P. canis, and show the 
same chromatin masses. 
Piroplasma bovis. 
After examining a considerable number of blood films, each of which 
contained only a few parasites with negative results as regards the 
finding of dividing forms, we obtained a slide prepared from a cow 
suffering from a high degree of infection, through the kindness of 
Mr J. R Jackson, M.R.C.Y.S., of the Board of Agriculture and Fisheries. 
In parts of this film as many as 30 infected corpuscles could be counted 
in a single field. Double but especially single pyriform bodies con¬ 
taining both dense and loose chromatin were common. The film was 
1 This secondary mass of chromatin was first described by us (Journal of Hygiene, 
x. 1906, p. 590) and has since been noticed by Christophers (1907, p. 22) in P. canis, who 
says “the loosely packed area described by Nuttall and Graham-Smith is almost invariably 
present,” and by Fantham (1907, p. 303) in P. bovis. 
