STUDIES ON CILIATED CELLS 265 



Although, from these observations no definite conclusion as 

 regards the development of the basal corpuscles and the root- 

 lets, can be reached there is no indication of the formation of 

 cilia from pre-existing basal corpuscles. The chondriocontes 

 give rise to the cilia. The basal corpuscles and the rootlets 

 are, in all probability, formed by the special differentiation of 

 the chondriocontes remaining behind in the cell. 



C. DEVELOPMENT OF CILIATED CELLS IN THE EFFERENT TUBULE 

 OF TESTIS OF THE MOUSE AND RAT 



Contrary to the view of Hammer ('97), Henry^('99), Ach ('02) 

 and Jordan ('13), I could not find any division figure, either 

 mitotic or amitotic, in ciliated cells of the efferent tubules; the 

 regeneration of these cells is, rather, effected, as mentioned be- 

 fore, by the transformation of cells with brush borders ; the 

 ciliogenesis which occurs in this corresponds in all respects with 

 that of the embryonal stage; first, the chondriocontes increase 

 largely in number and are chiefly accumulated between the nu- 

 cleus and the distal cell-border (fig. 79). It is certain that they 

 are not derived from the centrosome, though nothing is known 

 of the manner of their increase. They then proceed towards 

 the distal cell-border and transform into rod-Uke corpuscles 

 arranged in linear rows (fig. 80). These rods can scarcely be 

 said to be basal corpuscles, for they stain in the same way as the 

 chondriocontes. They emit, at successive periods, short initial 

 cilia (fig. 81), which gradually lengthen (fig. 82). In figure 82 

 there is, as usual, a centrosome consisting of two granules, the ex- 

 istence of which indicates that the latter takes no part in the for- 

 mation of the cilia. That the process of ciliogenesis takes place 

 in cells with brush borders has been already referred to; the 

 developing cilia are seen to pass, not through the interspace 

 between the hairs of the brush border, but through their axes, as 

 represented in figure 84 (the cell to the right). Since the cilia 

 are longer than the hairs, it is evident that the former project 

 l)eyond the distal extremity of the latter, which can no longer 

 be detected in fully developed ciliated cells. 



JOURNAL OF MORPHOLOGY, VOL. 29, NO 1 



