341 
NOTE ON THE MODE OF MULTIPLICATION OF PIRO- 
PLASMA BOVIS AS OBSERVED IN THE LIVING 
PARASITE. 
By GEORGE H. F. NUTTALL, F.R.S. 
(One diagram.) 
In a previous paper, Nuttall and Graham-Smith ( Parasitology , 1908, 
vol. I. p. 134) described the appearances presented by P. bovis in 
stained films, and showed that they agreed with those of P. cams and 
P. pithed with regard to the presence of the “ budding ” or multiplica¬ 
tion forms. The multiplication of P. bovis in fresh blood films remained, 
however, to be described. 
Whilst conducting experiments on the treatment of cattle with try- 
panblue (Nuttall and Hadwen, Parasitology, 1909, vol. n. p. 236), I had 
an opportunity of studying the living parasite in films prepared from 
ear-vein blood of certain of our control animals. The films were pre¬ 
pared in the usual way, sealed with vaseline and as rapidly as possible 
placed in a Nuttall microscope-thermostat. 
Certain facts regarding the parasite have already been noted ( Para¬ 
sitology vol. II. p. 239): the existence of many large, single, ovoid or 
pyriform parasites differing from those observed in P. canis and a much 
higher percentage of dividing forms than is encountered in blood 
containing the canine parasite. It was also noted that P. bovis shows 
less active movement than P. canis in the amoeboid stage. Whereas, 
usually, a maximum of 5—6 °/o of dividing forms are encountered in the 
case of P. canis, no less than 13—16 °/ 0 of dividing forms may be seen 
in the case of P. bovis in some animals at certain stages of the disease. 
The accompanying diagram illustrates the mode of division of P. bovis 
and the character of its amoeboid movement as observed in fresh blood. 
The figures are selected from a series of sketches made whilst watching 
Parasitology ii 22 
