E. W. BERGER ON THE CUBOMEDUS^E. 65 



of only one kind of cells in the epithelium. In a tangential section 

 taken just through the tips of the epithelial cells (Fig. 25) I find 

 polygonal areas with a central dot. This section does not at all agree 

 with Schewiakoff s Fig. 8, in which he figures two kinds of cells. In 

 Fig. 25 there can be no evidence of two kinds of cells, unless both 

 kinds have like flagella, for these dots are the transverse sections of 

 flagella continued within the cells (Fig. 26). 



The epithelium, then, is flagellate, a flagellum to a cell. Whether 

 there are flagella on the epithelium covering the region of the con- 

 cretion, I could not determine. But I believe that in all other parts, 

 excepting, of course, the corneas, it is flagellated. The fibers (flagella) 

 of the simple eyes are evidently the flagella of the invaginated 

 epithelium. Each flagellum has a basal body, and I could in many 

 instances determine that it was dumbbell-shaped (Fig. 12). This fact 

 was not always evident, however, and it was only occasionally that I 

 felt sure of it. Often the flagella showed only a general thickening 

 within the cells (Fig. 26) while, again, the thickening (basal body) 

 might be quite localized near the surface of the cell. Each flagellum 

 extends into its cell, and occasionally I could trace one clear past the 

 nucleus into the subepithelial nerve-tissue (Fig. 26), just as I did for 

 the axial fibers of the retinal cells of the simple eyes. In those 

 instances in which I could do this, the fibers could so clearly be 

 traced that little if any doubt can exist. I have thus made bold 

 and have drawn the flagella as continued through their cells into the 

 subepithelial nerve-tissue for all the cells of the epithelium of Fig. 12. 



A word on the epithelium covering the network cells of Fig. 13. 

 Conant and Schewiakoff here describe fibers from the supporting 

 lamellas that pass in bundles in among the network cells. These 

 fibers are supposed to be a part of the supporting lamella which 

 reaches out to be a support for the epithelial cells. (Schewiakoff also 

 describes similar fibers for other parts of the epithelium.) Now, as 

 Conant himself shows in Fig. 13, these coarse fibers are not of the 

 same consistency and staining capacity as the supporting lamella. I 

 found them to stain just like the intracellular parts of the flagella or 

 like the central continuations of the axial fibers of the cells of the 

 simple eyes. I could, also, occasionally trace them to the surface of 

 the epithelium, and beyond, when they became continued as short 

 blunt processes or flagella (Fig. 13). I, therefore, conclude that they 

 are sensory fibers like those I have described for the other epithelial 

 6 



