THE H^MOl'LAGELLATES. 



299 



Forms Parasitic in Avian Hosts. 



T. ziemanni (Lav.). (Synn. Spirochseta z. [Lav,], Scliaud., "Hoema- 

 mceba" z. Lav.; the " Leucocytozoon" of Danil.). Schaudinn, who has 

 fully described the life-history of this form (see above, p. 242), does not give 

 the actual dimensions. According to Laveran (37) the size of the female 

 gametocytes in the resting, intra-cellular condition, varies from 12 — 21 fi 

 by 4 — 7 fi, the male ones being slightly less. The length of the micro- 

 gametes (" flagella ") is from 20 — 25 /x. The ordinary indifferent indi- 

 viduals are characterised by their extremely Spiroclijeta-like facies and 

 their habit of remaining united together in pairs after division. Hosts : 

 (V.) Athene noctua, Little Owl, also Syrnium aluco (see below, under 



Fig. 51. 



Fig. 52. 



Fig. 53. 



Fig. 51. — T. johnstoni. g = deeply-staining granule at 

 distal extremity of flagellum. X 1500. (After Dutton and 

 Todd.) 



Fig. 52. — T. sp., from Senegarabian birds, x 1500. (After 

 D. and T.) 



Fig. 53. — T. sp., from Indian birds (Hanna's T). (After 

 Hanna.) 



T. avium) and "a little white owl from Cameroun " (Ziemann [121]), in 

 which sexual forms were seen; (I.) Culex pipiens. 



T. johnstoni, Dutton and Todd, 1903. Length 36— 38/^, width 1-4 to 

 1'6/i. This parasite resembles T. ziemanni in shape, being also markedly 

 spirochsetiform (fig. 51). The undulating membrane is narrow and poorly 

 developed. The most interesting morphological point is the absence of 

 any free continuation of the flagellum. This terminates abruptly, at the 

 end of the body, in a distinct, deeply-staining granule (g), which is pro- 

 bably of centrosomic nature. This species was found in small birds 



