THE SPERMATOPHORE IN ARENICOLA 1003 
minutes; in A. claparedii, in from three to eight minutes. (2) 
With a hypodermic syringe, sufficient preserving fluid is injected 
to distend the body; the whole worm is then immersed in the pre- 
servative. After hardening, the nephridia, when dissected out, 
have the shape and relations described above. 
Details of the methods of preservation will be reserved for a 
later paper in which the chromatin changes and other histological 
matters will receive attention. It will be sufficient now to state 
that testes preserved in strong Flemming, Bouin and vom Rath 
fixing fluids have given best results. The forming spermatophores 
have been studied in fresh body fluid, stained with methylen blue 
or neutral red; or in smear preparations killed by exposure to 
osmic acid fumes and fixed in Merkel or in vom Rath; or from 
sections prepared by squirting body fluid, freshly drawn, imme- 
diately into hot corrosive-acetic or Flemming, then hardening in 
alcohol in the usual way and sectioning in paraffin. Warm iron 
haematoxylin and Bordeaux red or saureviolett and fuchsin have 
been among the most successful stains. 
As the author has elsewhere published a description of the rela- 
tions of the blood vessels to the nephridia in the Arenicolidae, 
the following brief description will suffice here. Each nephridium 
of A. cristata is supplied with blood by a branch of the ventral 
blood vessel. This afferent vessel, on approaching thenephridium, 
branches to the setal sac and gill (if present), to the integumentary 
vessels, notably the dorsal-longitudinal, and to the nephridium. 
The branch to the nephridium enters the anterior angle of the 
sagittate funnel and after traversing it, passes on to the upper. 
surface of the body of the nephridium, which it crosses diagonally 
from the anterior inner to the posterior outer side. Peripherad 
to the nephridium, it joins the nephridial longitudinal vessel. 
From the point of emergence from the funnel on to the body of the 
nephridium to its juncture with the nephridial longitudinal ves- 
sel, the blood vessel is designated the gonadial vessel, since upon 
it the gonad is found. Gonadial tissue is also found, to a shght 
extent, upon the nephridial longitudinal just anterior to its attach- 
ment to the gonadial vessel (plate figs. 1-6). These figures show 
the location and relative size of the gonads in the several species. 
