204 



SPOROZOA. 



140. Toxoplasma canis Ugo Mello. 



Toxoplasma canis, Ugo Mello, 1910, pp. 359-63 : Minchin, 1912, 



p. 389; Carini & Maciel. 1913, pp. 681-3; Castellani & Chalmers, 



1919, p. 489; Boez, 1921, pp. 479-82; Wenyon, 1926, p. 1047. 



■f Toxoplasma canis, Donovan (first recorded in Wenyon, 1926, 



p. 1357). 



In fresh preparations the organisms are transparent, 

 colourless, immobile, semilunar or oval in form, rarely rounded 

 or pyriform. Stained with Giemsa each organism is a clear 

 blue homogeneous mass, surrounded by a transparent and thin 

 envelope. It contains one or (rarely) two chromatic masses 

 representing the nucleus, which are stained reddish- violet ; 

 generally rounded, but sometimes irregular, oval or linear in 

 form. The organism occurs singly or in groups of any number 

 up to sixty in endothelial cells, leucocytes, or cells of the spleen 

 or kidney. 



Habitat. — In the endotheHal cells or cells of the spleen or 

 kidney of the dog : India (locality not cited). 



141. Toxoplasma eolumbsB Yakimoff & Kohl-Yakimoff. 



(Fig. 100.) 



Toxoplasma columbse, Yakimoff & Kohl-Yakimofi, 1912, p. 198. 

 "fHaemogregarina francae, de Mello, 1915, pp. 93-4, pi. ii, figs. 1-10. 

 fLeucocytogregarina francee, de Mello, de Sa, de Sousa, Dias, & 

 Noronha, 1917, p. 13. 



Toxoplasma francee, NoUer, 1920, p. 914. 



Toxoplasma columhse, Noller, 1920, p. 914. 



Toxoplasma francse, Wenyon, 1926, pp. 1043, 1047. 



Toxoplasma columbse, de Mello, 1935 a, p. 706 ; 1937 a, p. 111. 



Parasite has a circular form when at rest, but shght move- 

 ments in the interior of the white cell change the form to a 



Fig. 100. — Toxoplasma columhse Yak. & Kohl -Yak. 

 A, young form ; B, C, schizogony. (After de Mello.) 



pointed one, with the nucleus in the rounded portion. Nucleus 

 in the fresh state strongly refringent, surrounded by such 

 clear protoplasm that it has the appearance of a vacuole. 



