498 H. B. FANTHAM. 



tion, but usually polar (figs. 2 and 3), tliat is, nearer to the 

 rounded or blunt end of the pyriform trophozoite. 



The smaller ovoid forms of the parasite measure 0"5ju to 

 1*5^ in diameter, while the pear-shaped forms are from 2 fx 

 to 3^ long, and from 1 /u to 1*5 /x broad. 



Four pyriform bodies are sometimes seen in the red 

 corpuscles of the peripheral circulation (fig. 10), but rarely 

 more than four. In the spleen six and eight small pyriform 

 bodies may occur in an erythrocyte (fig. 13). In some cases 

 in the spleen they are rather more irregular in shape than 

 strictly pyriform, affording examples of the so-called "amoe- 

 boid " trophozoites (figs. 14 and 18) known to occur in other 

 species of Piroplasma, and first described by Piana and 

 Galli-Valerio in the case of P. can is. 



In one case a vermiform trophozoite was noticed with a 

 chromatic appendage. This had been fixed and stained 

 towards the conclusion of the act of entering a red blood 

 corpuscle (fig. 19). Flagellate forms of P. can is have been 

 described by Bowhill and Le Doux (2), of P. equi by 

 Bowhill (1), and of the Piroplasmata of cattle by Lignieres 

 (30) and others. The suggestion that such flagellate forms 

 may possibly be microgametes seems to me premature and 

 doubtful in the present state of our knowledge, as the 

 " flagella " described by Bowhill and Le Doux are beaded, 

 and may really be only pseudopodia. 



Another vermiform or gregariniform, but entirely intra- 

 corpuscular, trophozoite, containing a chromatic dot attached 

 to an irregular rod-shaped portion of chromatin, is shown in 

 fig. 16. 



The cytoplasm of P. can is is described by Nuttall (41) as 

 " vacuolated or trabecular." In the case of the smaller 

 organism, P. muris, the protoplasm is hyaline, and appa- 

 rently finely granular, though it is very difficult to observe 

 the finer structural details of so small an object through the 

 wall of the enclosing blood corpuscle. 



A clear zone of protoplasm often occurs around the 

 chromatin body in the case of some of the large trophozoites 



