Gr. H. F. Nuttall, H. B. Fantham and A. Porter 335 
place, although the parasite frequently altered its position within the 
corpuscle. Similar forms are encountered in stained preparations. In 
two cases, one of which we illustrate (Diagram 3 B), two parasites 
appeared to be formed and to separate, but they may have remained 
connected by an invisible band of protoplasm. That such appearances 
are very deceptive has already been noted by Nuttall and Graham-Smith 
in the case of P. canis, and the observation (one of two) recorded in 
Diagram 3 C also indicates the need of caution in interpreting 
appearances when dealing with the still more minute parasites of East 
Coast Fever. Thus, in the figure referred to, the two connected pear- 
shaped portions of an apparently dividing parasite, formed a single mass 
Diagram 2. 
Fig. A. Showing the movements and changes of form of a single intra-corpuscular para¬ 
site during the period 19'—43'. Observation at 37° C. ; 2. in. 09. (G. H. F. N.) 
Fig. B. Similar to A. Period of observation 30'—225', at 38° C.; 12. ii. 09. (A. P.) 
when the corpuscle vanished (372'), only a small particle being seen to 
lie beside it. To have satisfied ourselves that actual division had taken 
place we should have observed a wide separation of the supposed 
daughter cells, but this we were never able to do, neither could we 
observe the escape of one of the newly-formed parasites from the infected 
corpuscle, as Nuttall and Graham-Smith were able to see in P. canis. 
It is possible, however, that what we have figured at C 265' may represent 
an early stage of division, and that, if the corpuscle had vanished at a 
later stage, two separate parasites might have been seen. Again and again 
