STUDIES ON AVIAN H.T'IMOPROTOZOA. 673 



29 ,u, lO/j, and 6h ft respectively. The flagellum of these 

 trypanosomes is usually comparatively loii"- (from 9 to 11^), 

 being often longer than in the largest individuals of the 

 fusiform kind. The kinetonucleus is always very near the 

 aflagellar end, which is short and conical. The trophonucleus 

 varies in shape; it may be moi'e or less rouud, but it is often 

 considerably elongated in a direction transverse to the longer 

 axis (figs. 52-54). 



It is noteworthy that in this earlier case no forms have 

 been observed which correspond to the larger fusiform 

 trypanosomes of the other series (case B). The parasites, 

 which are no longer very small — which are becoming inter- 

 mediate in size — such as the individual drawn in fig. 50, are 

 obviously approaching in character the wide, stumpy forms, 

 and differ appreciably from the intermediate-sized indi- 

 viduals of the fusiform variety in the features already 

 indicated, namely, the broader body, the longer flagellum, 

 and the abruptly terminating aflagellar part (cf . with figs. 

 43,44, from the other case). 



Many of the individuals in the above-described series of 

 *' small" parasites, including both fusiform and stumpy 

 ones, show a cytological peculiarity which is at first some- 

 what puzzling. This feature is a row or chain of granules, 

 which take up the red stain strongly, aud which are very 

 closely apposed to each other, giving the idea of a thick, 

 beaded line (figs. 42-44, 47-50, and 54). This chain runs 

 approximately parallel to the flagellar border of the undulat- 

 ing membrane, often following its curves closely, and it is 

 frequently more deeply staining and prominent than the 

 flagellar border itself. It begins near the origin of the 

 flagellum, and always ceases with the limit of the body, at 

 the opposite end, i.e. it never becomes free, as anything 

 corresponding to a free flagellum. At first sight this line 

 might be regarded as representing a new flagellum, formed 

 either de novo or by a splitting of the old one, the parasites 

 showing this appearance being therefore in the act of com- 

 mencing- division. After studying several of these individuals, 



