190 H. M. WOODCOCK. 



the locomotor apparatus exactly as in the case of an indifferent 

 Trypanosoma, aud finally the eight little male Trypanosomes 

 (f, 31. T.) break away from the central residual mass. They 

 are easily distinguishable from the other forms by their 

 minute size and by their flagellar apparatus, which is, rela- 

 tively, much more strongly developed, and gives them an 

 unusual degree of activity. 



Schaudinn finds that these male Trypanosomes (homo- 

 logous with microgametes) in the gnat are quite incapable of 

 further development. They cannot divide and soon die off, 

 even though they pass into the blood of the owl. It should 

 be pointed out that the trophonuclei of the male Trypano- 

 somes have already undergone reduction during the second 

 nuclear division in the parent gametocyte,^ and now possess 

 only four chromosomes each ; an important difference in this 

 respect is shown by the kinetonuclei, which have not been 

 reduced (cf. below, p. 197). Schaudinn considers that the 

 reason for the inability of a male Trypauosome to live inde- 

 pendently is to be found in this early reduction of its tropho- 

 nucleus and the consequent derangement of metabolism. 



(c) Ookinete of Female Character and its subse- 

 quent history in the Gnat. 



The cytoplasm of a female ookinete (fig. 10 a) is fairly 

 dense, with dark staining bodies of reserve material. The 

 nucleus is somewhat smaller, relatively to the size of the body, 

 than in an indifferent ookinete. Nuclear changes bring about 

 the formation of a male and female nucleus, exactly as de- 

 scribed for the male ookinete, but in the present instance it 

 is the male nucleus which ultimately degenerates. As before, 

 this gives rise,by successive divisions, to eight daughter-nuclei, 

 which pass into the hinder region of the body (b and c, m.n.). 

 Each of them becomes distinctly separated into trophic and 

 kinetic portions, but after this the eight double-nuclei gradu- 



• The author leaves a minute description of the process for his detailed 

 memoir. 



