84 
Equine Piroqdasmosis 
DESCRIPTION OF PLATE III. 
Nuftallia equi. Illustrating chiefly its mode of multiplication in the circulating blood, 
as shown in Giemsa-stained blood-fllms. Drawings in water-colour, made by 
C. Strickland with the aid of a camera-lucida and selected from a large number of 
figures made from freshly-stained films. 
Fig. 1. Small free parasite. 
Fig. 2. Small parasite shortly after its entry into a corpuscle. 
Figs. 3-8. Successive stages in the growth of parasites which may be either amoeboid 
(Figs. 5, 6) or assume more or less temporarily the piriform shape (Figs. 4, 7, 8). 
Figs. 9-19 indicate successive stages in nuclear division. The chromatin mass, which has 
hitherto been rounded or oval, becomes elongated and bent in conformity with the 
external contour of the parasite (Figs. 9, 10); the terminal and middle portion of the 
chromatin band becomes swollen (Fig. 11), and the strands connecting the three 
growing masses become thinner (Fig. 12), whilst the central mass in turn sub-divides. 
In some cases (Figs. 13-1.5) the strand leading to one of the smaller masses of 
chromatin ruptures before the central mass shows signs of division; in other cases 
(Figs. 16, 17) the central mass may show signs of division at this stage. In the next 
stage (Figs. 18, 19) that which was the central mass is clearly divided, but a fine 
chromatin thread still connects the daughter nuclei. 
Figs. 20-22. Nuclear division is here complete, there being four distinct masses of 
chromatin which are usually of about the same size ; the blue-staining protoplasm is 
beginning to collect around each nucleus. 
Fig. 23. A typical cross-form, with, the chromatin masses situated at the ends of the 
cross which is formed of four pear-shaped elements joined at their tapering 
extremities. 
Figs. 24, 25. The four young parasites have now separated within the corpuscle, no 
residual body being discernible. 
Figs. 26-28. Groups of four parasites derived from cross-forms which have escaped from 
ruptured corpuscles. In Fig. 28 one of the four parasites has become separated 
from the group. 
Fig. 29. Two free parasites which would presumably have entered a fresh corpuscle 
either singly or together. 
Figs. 30-32. Stages of division leading up to the formation of three or possibly four 
parasites. 
Figs. 33, 34. Groups of three small parasites inside (33) and outside (34) a corpuscle. 
Fig. 35. Unusual appearance presented by two fairly large parasites, both of which are 
preparing to undergo division as evidenced by the structure of the chromatin. These 
parasites would have presumably given rise to six or eight parasites. 
Figs. 36-40. Bounded, piriform or amoeboid parasites which show the chromatin drawn 
out and situated peripherally; 36 and 37 show a central vacuole. 
Figs. 41, 42. Corpuscles containing two and three parasites respectively. 
Figs. 43-45. Appearances suggesting that simple division of one cell into two may 
occasionally take place. 
Figs. 46, 47. Single piriform parasites closely resembling Piroplasnia. 
