256 S. SAGUCHI 



of the centrosome; Tschassownikow especially points out that 

 the ciliated cell, though it shows no karyokinetic figure, can 

 scarcely be said to be incapable of undergoing division, for it 

 is provided with organs of cell-division, i.e., the nucleus and the 

 centrosome. On the other hand, many of the investigators 

 (Hammer '97, Gurwitsch '01, Maier '03, Wallengren '05, Er- 

 hard '10, '11, Gutheil '11) believe they have found mitotic fig- 

 ures in ciliated cells. Gurwitsch represents in his figure 19, a 

 cell with a nucleus at the spireme-stage, which he takes as a cil- 

 iated cell; judging from his figure, however, it seems to me that 

 the cell has no cilia and basal corpuscles, but a relatively high 

 cuticular border. Just as little is certain whether the mitotic 

 figures found by Maier in the epithelium of the gills of Triton 

 and by Erhard in ependyma cells of an Acanthias embryo belong 

 to ciliated or non-ciliated cells. On the contrary, the observa- 

 tion of Erhard in the typhlosoles, and especially that of Wallen- 

 gren on gills of Anodonta appears to me to admit of very little 

 doubt. 



In the intestines of Anodonta and Helix and in the gall duct of 

 Helix I have been able to follow the karyokinetic process of the 

 ciliated cell, from the prophase to the anaphase. In the follow- 

 ing I deal wdth the intestine of Anodonta as a representative of 

 such cells. 



Prophase (figs. 17, 18). The fu'st change of the nucleus con- 

 sists, as usual, in the formation of the spireme; the cytoplasm 

 becomes clear and the chondriocontes, which gradually grow 

 pale, are scattered over the whole of the cytoplasm. At first 

 the basal corpuscles still stain deeply, but afterwards they dis- 

 appear. Contrary to the view of Wallengren ("05) I have found 

 that the cilium and the basal corpuscle become lost simultane- 

 ously. All of the cilia and the basal corpuscles, however, do not 

 disappear suddenly, but by degrees, so that it often occurs that 

 a few basal corpuscles with cilia are left behind for some time 

 (fig. 19) ; moreover I have noticed, in the intestine of Helix, cells 

 with distinct cilia, even in the metaphase. The ciliated cell in 

 the resting condition is long and narrow in shape; but on enter- 

 ing upon the karyokinetic process it becomes swollen where the 



