78 
Equiile Pit'opJasuiosis 
multiplication, like that of P. bovis, is slower than in F. canis, but 
otherwise it is similar, and consequently requires no further description. 
Very large transitorily piriform parasites are frequently observed as in 
P. bovis. 
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z 
3 
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S 
Diagram VIII. P. caballi. Illustrating appearances seen in Giemsa-stained parasites. 
Selected figures from a large series of coloured drawings by C. S. made from films 
derived from Horses I and III and from films supplied by Dr Marzinowsky. The 
figures show the mode of multiplication. The blue-stained protoplasm is indicated 
by light stippling, the deeply-staining chromatin by black, and the pink or faintly- 
staining chromatin by close stippling. The contours of the corpuscles are schema¬ 
tized. 
Fig. 1. Single piriform parasite which has recently entered a corpuscle. A deeply- 
staining chromatin mass lies to one side of the pink-staining bod.y and upon or 
within a small spherical mass of faintly staining chromatin. 
Figs. 2-4. Single parasites which have developed in size. Such parasites may be rounded 
but usually assume a piriform shape whilst slightly altering their form. The chro¬ 
matin mass increased in size and frequently becomes elongated. 
Fig. 5. Single parasite showing a large irregular faintly pink-staining chromatin mass. 
Fig. 6. Parasite with dark-staining chromatin mass prolonged into a thread which 
terminates into a bead-like mass. 
Figs. 7-9. The chromatin protruded in a fork-like manner into the buds of blue-staining 
protoplasm. (Figs. 7-18 as in P. canis, P. bovis and P. pithed.) 
Figs. 10-15. Showing more advanced stages of multiplication, a large mass of chromatin 
being seen at the point of bifurcation at the base of the buds. 
Fig. 16. Showing the separation of the chromatin masses in the daughter cells which 
remain connected at their pointed ends. 
Fig, 17. Newly-formed daughter cells still containing drawn-out masses of chromatin. 
Fig. 18. Mature pair of piriform parasites, and which are ready to separate and escape 
from the corpuscle. 
