264 S. SAGUCHI 



In this they do not pass into the alveoli, but ascend along the 

 striae, which are nothing but nodes of the alveolar walls in the 

 cuticle. Soon all the striae are occupied by the immigrant 

 chondriocontes, so that deeply staining parallel striae occupy the 

 same place as the alveolar ones (fig. 25). These, however, are 

 not always parallel to the radii, sometimes they are more or less 

 inclined in one direction, as seen in figure 25. This is, in all 

 probability, due to the previous inclination of the alveolar walls. 

 At successive periods the mitochondrial striae gradually grow 

 pale; there are, however, cases in which it occurs only after com- 

 pletion of the development of the cilia. Next, they emit from 

 their distal ends minute faintly stained prolongations (fig. 26), 

 which are the young cilia. At the beginning they are relatively 

 thick and short; later, they lengthen out (fig. 27). The chon- 

 driocontes are not used up in the formation of the cilia, but a 

 number of them remain behind in the cell, especially gathered 

 below the cuticle. From this manner of development it is pos- 

 sible that some of these chondriocontes are in continuity with 

 the cilia, and give rise to the so-called rootlets. 



2. The pharnyx of Rhacophorus larvae. The ciliogenesis begins 

 in a larva about 15 mm. in length. The chondriocontes, growing 

 more and more pale, ascend along the cuticular striae and project 

 beyond the limits of the cuticle (fig. 56). At first they are short, 

 and often curved in the shape of hooks, but afterwards they 

 lengthen out. 



3.. Tela chorioidea of Amphibian larvae (Hyla, Rhacophorus 

 and Hynobius). In the early embryonic stage, the tela epi- 

 thelium of Hyla consists of flattened cells, which contain numer- 

 ous yolk-spherules and chondriocontes; the latter are accumu- 

 lated near the upper border of the cell (fig. 34). In the next 

 stage the cilia make their appearance (fig. 35). From the fact 

 that the cilia are produced in that part which coincides with the 

 accumulation of chondriocontes, the inference is warranted that 

 there may be a genetic connection between the two. 



4. The ciliated infundibulum of Hyla larvae. The chondrio- 

 contes are collected below the cuticle through which they pass 

 out of the cell in order to form the cilia; the continuity between 

 the two is readily discernible in favorable conditions (fig. 40). 



