THE HJiMOFLAGELLATES. 301 



T. paddse, Lav. and Mesn., 1901. Length 30-40 /x, breadth 5-7 ju. 

 From the description this form (fig. o-l) appears to be of a very similar type 

 to the last. The undulating membrane is perhaps rather better developed, 

 however, and the free part of the flagellum is shorter. The anterior end is 

 usually very attenuated, sometimes so much so that "it appears as though 

 there was a flagellum at each extremity." The cytoplasm shows fine 

 longitudinal striations. (V.) Host: Padda oryzivora (from the Paris 

 markets), in whose blood also Halteridium danilewskyi is often 

 found.^ 



T. polyplectrum, Vassal, 1905. Length 46 /x, of free flagellum 12 /t ; 

 breadth 5a«. Anterior end extremely attenuated and flagelliform, even 

 more pronouncedly than in T. paddae. From a pheasant (Poly- 

 plectrum germani) in Annam. 



T. avium, Danil., 1885 (Laveran emend., 1903). Length 35 — 45/t, 

 inclusive of flagellum. Body elongated and fusiform in shape (figs. 16 r, 

 55); anterior end tapering. Undulating membrane well-developed, with 

 a longitudinal striation or fold running in it. Laveran found the para- 

 sites iu Syrnium aluco, Tawny Owl. Danilewsky observed Trypano- 

 somes in various phases (fig. 3) in owls (sp, indet.) and also in " roller- 

 birds "(Coracias garrula). Their size is given as from 20 — 60/iby 7— 8/i. 

 Laveran (36) thinks it not unlikely that the Trypanosome in the rollers is 

 a distinct species. It is interesting to note that Laveran mentions the 

 occurrence, in the Tawny Owl which contained T. avium, of "Hsem- 

 amoiba" ziemanni and "H." (Halteridium) danilewskyi. Is it 

 possible that the latter HiBmatozoan represents the corresponding phase 

 of T. avium which the former does of T. ziemanni P 



Novy and McNeal's work (81) on the Trypanosomes of birds is most 

 difficult of exact estimation from a systematic standpoint for the reasons 

 already given (pp. 281, 282). In only a single instance were their numerous 

 cultures of the parasites successful in giving rise to Trypanosomes, when 

 injected into the blood. This, certainly, does not point to the organisms 

 having been at the time in a very healthy condition ; on the contrary, 

 some of the authors' excellent photomicrographs strongly suggest abnormal 

 and involuted phases (cf. their pi. 7) 



Novy and McNeal consider they have investigated at least four different 

 species. A parasite identified as Danilewsky 's T. avium is most frequent. 

 Two types are recognised (corresponding to that worker's majus and 

 minus). One is of less frequent occurrence, and measures 50/* by 6/^, 

 the flagellum being 15 — 20 /x in addition; the other (more common) is 

 20 /i by 3 — 5 /«, the flagellum 10 f^ extra. This smaller variety is thought 



According to Thiroux this association is purely accidental, there being 

 apparently no connection between these two parasites (see, however, under 

 T. avium. 



