CELL ULTKASTKUCTIRE L\ MAMMALS 



Fig. 3. Detail of a proximal tubular cell of the mouse kidney. A number of struc- 

 tures are seen which can be encountered in most mammalian cells. The nucleus (N) 

 with its triple-layered envelop. Two mitochondria are present, one sectioned longi- 

 tudinally (MI), the other cross cut (M2). In addition to several microbodies (m), 

 Golgi membranes and vesicles (Go) a dense large body (D), may be seen. Magnifi- 

 cation 67, OOOX 



to five longitudinal fine filaments. In man, mediate stage between the ordinary brush 

 the stereocilia are found in the duct of the border extensions and the ciha. 

 epididymis (Fig. 6). Their function is not Cilia. The ciha are extremely long ex- 

 clear because they do not have any con- tensions of the apical cell cytoplasm. They 

 tractibility. They seem to form an inter- are coarser than the stereocilia and display 



95 



