THE HJIMOFLAGELLATES. 213 



There can be little doubt that much has yet to be ascer- 

 taiued concerning the details of nucleai- structure in most 

 forms. We have above described the complexity of the 

 nuclear apparatus in Try panomorpha noctuse, its division 

 into two distinct parts, trophic and kinetic, and the inti- 

 mate connection of the latter with the locomotor apparatus. 

 It must be remembered, moreover, that Try panomorpha 

 is not the only Trypanosome in which this highly complex 

 condition exists. Schaudinn finds a complete parallel in 

 Trypanosoma ziemanni (the '' Spirochfeta "-form) ; 

 in this parasite the nuclear apparatus is even more com- 

 plicated; owing to the fact that the number of " chromo- 

 somes" is sixteen, as compared with eight in the first-named 

 form. Again, according to Prowazek's recent investigations, 

 T. lewisi and T. brucii also possess the same funda- 

 mental type of nuclear structure. Indeed, the system of 

 axial spindles produced by successive divisions of the karyo- 

 centrosome is even more elaborate in the former parasite 

 than in Trypanomorpha. In both forms, the number of 

 trophonuclear chromosomes was clearly seen to be eight; 

 those of the kinetonucleus were more difficult to make out, 

 owing to the compacter form of the latter body. The only 

 other case in which a definite number of chromosomes has 

 been made out is the trophonucleus of Trypanoplasma 

 borreli. Here Leger describes eight dumbbell-shaped chro- 

 mosomes^ radially arranged around a central grain (karyo- 

 centrosome). These instances would seem to suggest that, 

 with finer and more detailed investigation, the nuclear 

 apparatus of Trypanosomes will be found to show a greater 

 uniformity of complex organisation than is so far known. 

 Our present knowledge of the nuclear elements in the 

 majority of Trypanosomes relates chiefly, however, to their 

 position and general appearance, and is soon summarised. 



The trophonucleus (nucleus) occupies a position usually 

 about the middle of the body (figs. 16 b — d, p, 17 j and k) ; 

 it may, however, be either in the flagellate half, as in T. 

 ' Thej may be divided, forming 16 small chromatic masses. 



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