STUDIES ON AVIAiSr HyEMOPROTOZOA. 669 



and 6^ fx in total breadth, while that in fig. 35 is 44^ by Of fi. 

 Even the rather smaller forms of this kind (figs. 34, 36, and 

 38) are distinctly wider than the full-grown definitive 

 parasites, their breadth varying from 5i to 6 /t. Hence, in 

 general appearance these trypanosomes differ considerably 

 from those of the first type. 



The aflagellar end is prolonged for some distance (6 to 

 8 ju) beyond the kinetonucleus ; it may be fairly wide and 

 somewhat blunt (fig. 36), or slender and tapering (fig. 37), 

 but it is never so finely drawn-out and attenuated as in the 

 case of the definitive individuals. The free flagellum is 

 usually short, only about 4 to 4J ju long. The undulating 

 membrane is well developed, but the folds or pleats are not 

 usually so sharply separated from each other as in the case 

 of the other forms. 



The cytoplasm of these massive forms stains blue, deeply 

 and intensely.^ In structure it is quite different from that 

 of parasites belonging to the other type. As a whole it 

 is much coarser in texture and more granular. In the 

 majority of cases it does not appear to be of uniform character 

 throughout the body (figs. 34 to 36). In the aflagellar third 

 or so of the body it is loose and spongy, with large granules 

 more or less uniformly distributed ; but in the other two thirds 

 or so, i.e. in the region from the trophonucleus to near the 

 flagellar end, it is more compact, and the granules tend to be 

 closely arranged in longitudinal rows, of which there are usually 

 five or six. Thus the cytoplasm in this part of the body 

 appeai-s made up of narrow dark bands (composed of more 

 prominent granules, packed together), with between them 

 paler bands or zones of more finely granular (and hence less 

 deeply staining) cytoplasm. The extent to which this serial 

 arrangement of the larger granules is developed varies in 

 different individuals. In some they extend through two 



^ There is no question of this difference being due merely to acci- 

 dental variations in the staining; individuals representing the two 

 types of form have been fovmd on the same smear, and within a short 

 distance of one another. 



