142 



O. C. GLASEK. 



furthest away from the nucleus are the smallest, and finally only 

 minute scattered granules can be seen where one cell abuts upon 

 another. 



The mouth (;///.) is nearly perpendicular to the antero-poste- 

 rior axis of the body. On each side of it are two pear-shaped 

 patches of highly vacuolated ectoderm [which I described ('04) 

 as early stages of the external kidneys, two organs which in 



hv 



m t k 



i 

 bv 



I' ic,. 2. Pre-cannibal larva of Fasciolaria ; b.v., body vesicle; ejc./c., external 

 kidney; h.v., head vesicle; mac., macromere ; /nt/i., mouth. Zeiss D obj. 2 oc. 

 Drawn by Mr. Carl Kellner. 



Fasciolaria reach surprising proportions and probably take a most 

 active part in the excretion of waste products. 



The cells of the excretory organs differ from the ordinary 

 ectoderm cells chiefly in [the great size of their vacuoles and 

 nuclei. They resemble at this stage the ordinary ectoderm in 

 in the comparative indefiniteness of their boundaries, which 

 curiously enough are perfectly distinct at earlier as well as at 

 later stages of development. This disappearance and subsequent 

 reappearance of cell boundaries is due I believe to changes in 



