REMARKS ON PIROPLASMOSIS. 123 



intracellular i^arasites, such as the Malaria plasinodia, possess the bioh)- 

 gieal faculty of changing the blood pigment into visible, amorphous parti- 

 cles, which faculty is entirely wanting in the Piroplasina group. I will 

 not enter here upon a discussion of the relationship between these leucocy- 

 tophages and the trypanosomes, an idea which has been suggested in a 

 recent work, becaiise this relationship at the present time is not quite 

 clear. 



For the present, the following species of parasites may be referred to 

 one group : 



(1) Pirosoma higemmum aptly named by Theobald Smith on account 

 of its pear-shaped, double body. The parasite is free from pigment, is 

 situated in the red blood cells, and may be taken as a representative of 

 the whole group. . 



(2) Piroplasnia parvum. — This organism sometimes possesses a double 

 body, but is not pear-shaped in outline; it likewise is free from pigment 

 and is situated in the red blood cells. 



(3) Leishmani donovani and Ilelcosoina tropicum, both of these para- 

 sites are also free from pigment and therefore are classified with the 

 other two. 



