98 T. H. JOHNSTON AND J. B. CLELAND. 



In the latter description the characteristics of this new 

 genus are given as follows : — " In the earliest stage, the 

 parasite appears as a small rather irregular or amoeboid 

 body with a zone of pigment granules across the centre. 

 At first the nucleus of the red corpuscle is only slightly 

 displaced. With growth of the parasite the nucleus of the 

 red cell becomes pushed to one end of the corpuscle. Some- 

 times the parasite is oval or somewhat irregular in contour. 

 Sometimes it is round or lenticular. The elongated oval 

 form nearly fills the corpuscle : only a narrow pink rim 

 may be seen surrounding the blue body which moulds itself 

 upon the nucleus of the blood cell. Judging from the 

 analogy of other cases, it would seem that the spherical or 

 discoidal form is the gametocyte or final stage of the tro- 

 phozoite." 



"Two very distinct types were met with, resembling 

 each other in form but differing in their reactions to Leish- 

 man's stain. These no doubt represent sexual differences. 

 In the male type the body is faintly granular and stained 

 a delicate blue with numerous small pigment granules 

 scattered round the periphery. In the other or female 

 trophozoite the body is stained dark blue, the pigment 

 granules though numerous appear to be slightly larger at 

 times ; and varying numbers of vacuoles of different sizes 

 are always present. In the pale form vacuoles never occur." 



44 We propose to name the new genus with the characters 

 which we have described Haemocystidium, on account of 

 its rounded, turgid, more or less bladder-like shape and 

 appearance." 



Under this genus, they include Simond's Haemamoeba 

 metchnikovi, while admitting that it differed in size, rarely 

 exceeding half of the blood corpuscle, in the smaller number 

 of the pigment granules and in not displacing the nucleus. 

 They conclude by saying : — " It seems clear that Haema- 



