266 B. SAGUCHI 



Whether or not the ring-shaped corpuscles which I found in 

 cihated cells of the efferent tubule of the rat, are the same as the 

 'Zentralkorperballen' of Benda and Ikeda, I am not certain; I 

 have not, however, sufficient evidence to show that they have 

 any connection with ciliogenesis. It seems probable that these 

 structures, as well as the granules or threads described by Fuchs, 

 are similar to the chondriocontes. 



D. CILIOGENESIS IN THE DAUGHTER-CELLS PRODUCED BY MITOSIS 

 OF THE CILIATED CELL 



As already mentioned, the ciliated cells in the intestine of Ano- 

 donta multiply by mitosis; at the beginning of the metaphase 

 the basal corpuscles and the cilia disappear, and in the anaphase 

 the ciliogenesis sets in; the process is, in the main features, sim- 

 ilar to that of embryonic development of the cilia. The chon- 

 driocontes now give the previous staining reaction and are col- 

 lected above the nucleus (fig. 21). At successive periods, some 

 of these filaments proceed towards the cuticle, their upper ends 

 often swelling out into bulbous enlargements, from which the 

 cilia pass out through the cuticle (fig. 22). These granules are, 

 in all probability, not identical with basal corpuscles, but mere 

 local accumulations, of the mitochondrial substance. 



Summary 



1.. The ciliary apparatus is produced by the differentiation of 

 mitochondria or chondriocontes, whether the process occurs in 

 embryonic or in adult cells. 



2. The centrosome takes no part in the formation of the cilia. 



VIII. HENNEGUY-LENHOSSEK'S HYPOTHESIS 



Henneguy and Lenhossek, at nearly the same time ('98), but 

 independently, formulated an hypothesis that the ciliary appa- 

 ratus, especially the basal corpuscles aie derived from the cen- 

 trosome; an hypothesis which has since obtained some adherence 

 among histologists (Benda '00, Flirst '00, Holmgren '03, Fachs 

 '04, Joseph '05, Ikeda '06). The arguments in favor of this 



