THE HJIMOFLAGELLATES. 



215 



flagellum.^ In view of its essential nuclear character and the 

 fact that it serves as the directive centre for the locomotor 

 activities of the cell, and since, moreover, none of the other 



Fig. 18. — Trypanoplasma borreli, Laveran and Mesnil. 

 a.f. = anterior flagellnm ; p.f. = posterior do. ; m. = undulating 

 membrane ; T. = trophonucleus ; K. = kinetonucleus; /. z= fibril 

 (myoneme) ; c = centrosomic granule at base of flagellum. (After 

 Leger.) 



names given correctly indicates its real nature, the term 

 kinetonucleus has been adopted in this article to designate 



' According to Wasielewsky and Senn the " Geisselwurzel" (to call the 

 body for the moment by a non-committal name) is a blepharojjlast, i. e. a 

 purely superficial thickening or ectoplasmic differentiation (in botanical 

 language, a periplastic or kinoplasmic development), and bears in its origin 

 no relation to the nucleus. This view is now completely out of court. 

 Rabinowitsch and Kempner (89) considered it as a nucleolus, notwith- 

 standing the fact that it is nearly always extranuclear. The other two well- 

 known tlieories, namely, the centrosomic view of Laveran and Mesnil and the 

 micronuclear one of Bradford and Plimmer, have each a certain modicum 

 of truth. But, as Schaudinn points out, the kinetonucleus is much more 

 than a centrosome — possesses, in fact, a centrosome of its own — and, on the 

 other hand, it has not much in common with the " micronucleus " of 

 Infusoria, beyond the fact that it is of nuclear origin. A micronucleus is 

 essentially a sexual nucleus, its role being played when that of the meo-a- 

 or somatic nucleus is finished ; whereas here the kinetonucleus has primarily 

 a kinetic function, the other, the trophonucleus, being just as important 

 sexually. 



