1010 ELLIOT ROWLAND DOWNING 
accumulation of growing spermatophores. During December 
the diagonal muscles in the region of the first nephridium espe- 
cially and to some extent in the second are apparently becoming 
‘hairy.’ This appearance is due to the numerous long, fine blood- 
vessels attached at one end to a large vessel, the other floating 
freely in the body fluid. Similar vessels have been noted before 
Text fig. 1. Outline of the testis of A. cristata in October. The gonadial 
material lies around the blood vessel. The dotted area corresponds to that 
shown in detail in fig. 7, pl. 2. 
Text fig. 2. Outline of the testis of A. cristata in February. The dotted 
area corresponds to that shown in fig. 8, pl. 2. 
in A. claparedii and A. grubii by Gamble and Ashworth (p. 518) 
with no suggestion as to their probable function. They seem 
evidently a device for the better aeration of the body fluidsand the 
elimination of its wastes while it is heavily loaded with the devel- 
oping spermatophores. They disappear in A. cristata: in early 
summer when the sperm are fully formed. 
