484. RICHARD ASSHETON. 
Fie. 15.—Section of the epidermis of a 6-mm. tadpole, taken horizontally 
between the nasal depression and the developing gill-filaments. 
Fie. 16.—A piece of a gill-filament of an external gill of an 8-mm. tadpole. 
The ciliated cells are darker, and project slightly above the remainder. 
Fic. 17.—Diagram of the tail of a 12-mm. tadpole, to show the general 
arrangement of the long ciliated cells drawn in Fig. 18. The zigzag lines 
terminating in arrows show the course taken by particles as they are dashed 
from cell to cell across the tail fins. 
Fic. 18.—This shows three of the ciliated cells (C.), which are oblong and 
darker in colour than the surrounding polygonal non-ciliated cells. 
Fic. 19.—Side view of the embryo of Triton cristatus, showing the 
direction taken by currents of water due to the ciliation of the anterior end 
of the embryo. The two stars indicate a spot where the motion is very rapid— 
the stomodeum. 
Fic. 20.—The same embryo of Triton cristatus. A ventral view. 
Fic. 21.—An embryo 6 mm. in length of Triton cristatus, seen from 
the side. The arrows indicate the flow of water produced by the ciliation. 
Fic. 22.—A ventral view of the anterior end of the same embryo. 
