634 MlIJlIMIi ROCKliTHOxX AND K. A. MIN(J1IIN. 



of a trypanosoine is that the basal granule of the flagellum 

 represents the true blepharoplast, a body of the nature of a. 

 centrosonie, and that the kinetonucleus or German blepliaro- 

 plast is an accessory nucleus which is not represented in the 

 economy of a collar-cell or in flagellated organisms generally, 

 but which is a special feature of the genus Trypanosoma 

 and its allies, especially the geuera Try panoplasma, 

 Herpetomonas, Leishmania, and Crithidia, a nucleus 

 which doubtless possesses its own centrosome or centriole. 

 With regard to the function of the kinetonucleus, its close 

 association with the blepharoplast and the flagellar apparatus 

 has generally been held sufficient to justify the assumptiou 

 that it possesses a kinetic function, that is to say, that it is 

 a nucleus specially concerned with the regulation of the 

 function of locomotion. We require, however, more know- 

 ledge with regard to the relations of the kinetonucleus to 

 the life-cycle as a Avhole, and more particularly to the 

 phenomena of sex and sexual conjugation in these flagellates 

 before this point can be decided. We may refer in this 

 connection to the interesting experiments of Werbitzki (19), 

 who was able to obtain trypanosomes without a kinetonucleus 

 (termed by him " blepharoblast "), and found that such 

 individuals showed no difference, as rejrards their movements, 

 from the trypanosomes of normal structure. This result 

 seems to us to indicate that the flagellar apparatus of a 

 trypanosome is not so dependent on the kinetonucleus as is 

 generally supposed, and also to be strongly in favour of our 

 view that the basal granule of the flagellum, and not the 

 kinetonucleus, represents the true blepharoplast. AVerbitzki 

 seems, in fact, to have reduced his trypanosomes artificially 

 to the more primitive condition found in other flagellates and 

 also in collar-cells, a condition i]i which the organism 

 possesses a nucleus and a true blepharoplast, but no kineto- 

 nucleus. 



It may be objected to our conclusions that they are based 

 only on analogy, and that a collar-cell is too far removed 

 from a trypanosome in phylogeny and affinities to permit of 



I 



