STUDIES ON CILIATED CELLS 263 



in the pharnyx of Bufo) ; (2) first, the alveolar septa themselves 

 become transformed into the cilia, while the basal corpuscles 

 secondarily make their appearance at their basis (in the pharnyx 

 of Salamandra larvae). On the other hand, the observations of 

 Benda ('00), Fuchs ('04) and Ikeda ('06) on the efferent tubules 

 of the human testis, had a marked influence upon the develop- 

 ment of the so-called Henneguy-Lenhossek's hypothesis. Ac- 

 cording to these authors the centrosome, after multiplying by 

 repeated divisions, gives rise to the basal corpuscles, from which 

 the cilia develop. Wallengren ('05) studied ciliogenesis in the 

 daughter cells produced by the mitotic division of the ciliated 

 cell and found that, contrary to this view, the basal corpuscles 

 are developed, independently of the centrosome, within the 

 superficial portion of the cell-protoplasm, a view with which 

 those of Heidenhain ('99) and Erhard ('10) are in accord. Ach 

 ('02) asserts that the basal corpuscles are derived from granules 

 situated above the nucleus, from which they are cast off, while 

 Gutheil ('11) maintains that the cihary apparatus is developed 

 from the microsomes suspended on protoplasmic networks. 



B. EMBRYONIC DEVELOPMENT OF THE CILIARY APPARATUS 



1. The epidermis of Aviphihian larvae {Rhacophorus, Hynobius 

 and Hyla). The development of the ciliated cell in the epider- 

 mis of these larvae begins at an early embryonic period in which 

 the larvae are still enclosed within the gelatinous coat. The 

 epithelial cell which is preparing to transform into ciliated (fig. 

 23, the cell to the left) is always provided with a well-marked 

 cuticular border, the actual structure of which has been already 

 referred to above in the section ''Relations between the cilia and 

 the crust or cuticle." The cells in question are most commonly 

 large, so that the lower ends often reach the basement mem- 

 brane; most of these cells are laden with yolk spherules of various 

 size (figs. 24, 26), in the intervals between which mitochondrial 

 filaments (chondriocontes) course in different directions; they 

 are also gathered in considerable numbers below the cuticle. 

 At successive periods, these chondriocontes, after or without 

 becoming vertically arranged, pass into the cuticle (fig. 24). 



