THE ILEMOSPORIDIA 387 



From the foregoing it is seen that the development of piroplasms 

 appears to be of a type essentially similar to that of the hsem- 

 amcebse and haemogregarines. In the present fragmentary state of 

 our knowledge, however, it would be premature to generalize con- 

 cerning the development of these forms. The most noteworthy 

 feature of the development is the entire absence of flagellated forms 

 from the life-cycle. The alleged flagellate forms of P. canis in 

 the dog's blood described by Breinl and Hindle have been dealt 

 with above ; it only remains to be mentioned that Miyajima 

 obtained trypanosomes in cultures of the blood of calves suffering 

 from piroplasmosis, an observation which led to the discovery of a 

 trypanosome in calves not previously known to exist (see p. 283). 



Doubtful Genera of Hcemosporidia. A certain number of blood- 

 parasites have been described which at present are not sufficiently 

 well known to make it possible to assign to them a definite systematic 

 position. When more thoroughly investigated, many of them may 

 turn out to belong to other groups than the Heemosporidia ; it is 

 even possible that some of these bodies are not parasites at all, but 

 merely some forms of cell-enclosures. 



The genus Toxoplasma was founded by Nicolle and Manceaux (754) for 

 T. gondii, a parasite of the gondi (Ctenodactylus gondii) ; other species have 

 since been described namely, T. cuniculi, Carini, from the rabbit, T. canis, 

 Mello, from the dog, and T. talpce, Prowazek, from the mole. The organisms 

 in question are parasites of the white blood- corpuscles, and occur most 

 abundantly in the spleen or liver, causing a disease which is frequently fatal. 

 The parasite is a crescent-shaped body, with one end thicker than the other, 

 and containing a single nucleus ; they multiply by binary or multiple fission. 

 Nicolle and Manceaux regarded them as allied to LeisJimania, but their 

 resemblance to this genus appears to be purely superficial, since in Toxoplasma 

 no kinetonucleus is present, and in cultures no flagellated stage is developed. 



Elleipsisoma ihomsoni is the name given by Frana (441) to a parasite of 

 the blood of moles discovered by Thomson (524). It occurs as an amoeboid 

 intracorpuscular parasite with a single nucleus situated at the margin of the 

 body, which contains no melanin-pigment. Multiplication takes place ex- 

 clusively in the lung, and is by binary or multiple fission, according to Fran$a ; 

 the young forms are either vermiform, with the nucleus drawn out, or oval, 

 with a compact nucleus ; they penetrate into the corpuscles and grow there. 

 Fran9a considers this form to be allied to Toroplasma. 



The name Toddia bufonis is given by Franca (440) to certain bodies in the 

 red blood-corpuscles of batrachia, first described by Todd. The earliest stage 

 in the corpuscle is a small globule of chromatin ; Franca believes that the 

 parasite when it penetrates the corpuscle is reduced to its nucleus alone, and 

 that it gradually forms a cytoplasmic body which becomes substituted for 

 that of the corpuscle. As the cytoplasmic body is formed, crystals appear 

 in it, one large crystal or as many as three smaller ones. Finally the corpuscle 

 is seen with a si ightly hypertrophied nucleus pushed to one side, and its contents 

 consisting chiefly of substance which stains intensely blue with the Roman- 

 owsky stain, in which are the crystals and the nucleus of the parasite, now 

 3 to 3 '5 p. in diameter. No multiplication-stages have been observed. 



Globidium multifidum is the name given by Neumann (488) to a parasite 

 of the red blood- corpuscles of Gobius minutus and Arnoglossus grohmanni. It 

 was met with in the form of a cluster of some thirty to sixty merozoite-like 

 bodies, each 2'5 /* in length by 1*5 p. in breadth ; similar bodies were seen in 



