DIVISION OF COLLAR-CELLS OF OLATHKINA COKIACEA. 617 



Teiluny: dev Metazoenflimmei-zelleu keiuerlei aktiveu Anteil 

 nehraeu, so kaiin fur diese Zellen die Heuneguy-Leiilios- 

 seksche Theorie niclit mehr aufrechterhalten vverden." Thus 

 while maintaining- tlie centrosomic nature of the diplosome, 

 Erhard denies it for the basal gi-auules of the cilia in ciliated 

 cells. 



As regards the basal granules of the flagella in Protozoa, 

 evidence bearing on their nature is scanty to a disappointing 

 degree. The majority of investigators appear to ignore these 

 bodies. Schaudinn (17) found in Paramoeba the " Neben- 

 korper " acting as a centrosome in the mitosis; the tlagella 

 of the swartn-spore appear to arise quite independently of the 

 Nebenkorper, a body which, from Schaudinn's investigations, 

 gives the impression of being rather of the nature of a kineto- 

 nucleus than of a centrosome (pace Hartmann and Prowazek), 

 and which very probably contains its own centrosome (or 

 centriole), which acts also as the centrosome of the principal 

 nucleus in tlie mitosis. Prowazek (15) points out that the 

 flagellum of Flagellata may arise within the nucleus (" Kern- 

 endogener Ursprung" ) or outside it ; in the latter case the 

 flagellum may terminate in a "diplosome/' which again may 

 be quite free from the nucleus (as in the collar-cells studied 

 by us) or niay be connected with the nucleus by a " rhizo- 

 plast." In the nuclear division of Entosiphon, Prowazek 

 (16) found a " basalkorperartige Verdickung" at the origin 

 of each flagellum, and from this body a rhizoplast passing 

 back to the nucleus. At the division of the nucleus a " Centro- 

 nukleolusspindel" is formed. The basal granules do not 

 appear to influence the division of the nucleus in any way; 

 they divide, and two new flagella grow out from each pair. 



In his famous investigations on the trypanosome of the 

 little owl, Schaudinn (18) gives the following account of the 

 origin of the flagellar apparatus. The nucleus of the ookinete 

 contains a karyosome in which a "central grain" is surrounded 

 by eight chromosomes. By heteropolar division the single 

 nucleus divides into a larger nucleus, the trophic nucleus, and 

 a smaller, the kinetonucleus (" blepharoplast "). The kineto- 



