664 H. jr. WOODCOCK. 



the eye. If I passed over one in my search I doubtless took 

 it merely for a large leucocyte. 



4. Description of Trypanosoma Fringillinardm, n. sp. 



(a) As Found in the Birds. 



The trypanosomes from the chaffinch (Fringilla c celebs) 

 ahd the redpoll (Linota rufescens) most probably belong 

 to one and the same species. The trypanosome once noted, 

 but not described, by Ziemanii, in 1898, was most likely tliis 

 form; and the same applies doubtless to Petrie's observations 

 (21) in 1905. The occurrence of trypanosomes in the redpoll 

 has not been known iiitherto ; this bird is a new avian host 

 for the parasites. I regard the trypanosome from these two 

 birds as a distinct and new species, for which I propose the 

 name T. fringillinarum. 



I discuss below the question of the specificity of different 

 ti'ypanosomes, with reference particularly to avian forms. I 

 will merely give here the chief reasons which lead me to 

 consider all the different types met with in the chaffinch and 

 redpoll as belonging to one species. In the first place the 

 ordinary, or definitive form of the parasite, the type, that is, 

 which affords in the existing state of our knowledofe the 

 chief basis of morphological comparison in a systematic 

 study of different Trypanosomes, appears to be essentially 

 the same, as regards form and structure, both in the chaffinch 

 and in the redpoll (cf . for instance figs. 4 and 31 of individuals 

 from a naturally infected chaffinch with figs. 3 and 32 respec- 

 tively of parasites from a naturally infected redpoll). Again, 

 the forms which appeared in the blood of a chaffinch as the 

 result of inoculation with a culture of the redpoll-parasite 

 are also of a similar type (cf. figs. 1 and 28).^ Secondly, 

 although considerable polymorphism is shown, transition 

 forms occur, which are intermediate between the more 



' The fact that the inoculation of the parasites from the redi^oll into 

 the chaffinch was successful itself points to the specific identity of 

 the two forms. 



