1894. ] NEW YORK ACADEMY OF SCIENCES. 239 
chromate. In the course of from 24—48 hours pieces should be 
placed in the silver nitrate solution at intervals. After having 
been in the silver bath for one to several days or more, a piece 
found by trial section, by hand, to be impregnated may be 
washed with strong alcohol (95 %) a short time, 5 hour or so, 
stuck on a microtome block and cut in 95% alcohol into sec- 
tions of suitable thickness, say 40-100 x. After Leing washed 
in 95% alcohol they may be cleared in Ol. Origanum Creticz, 
rinsed in xylol and mounted in dammar balsam (or Canada bal- 
sam dissolved in xylol) without a cover slip, care being taken 
that the layer of balsam is as thinly spread as is possible in 
order to just cover the sections. It is best to dry the balsam 
quickly by placing the slides in an oven at 45°-55° C. 
This method has been tried principally thus far upon the 
adult human cerebrum and cerebellum and has yielded some ex- 
cellent pictures of pyramid cells, of neuroglia, and especially of 
the Purkinje cells. In the hen’s brain it has also given pictures 
of the granule cells of the cerebellum with their axis cylinder 
processes dividing T-shaped in the molecular layer. It is ap- 
parently inferior to the ordinary rapid method for embryonic 
material. 
THE FUNNELS AND TERMINAL VESICLES OF THE 
HIRUDINEA. 
(CLEPSINE, NEPHELIS, AULASTOMA. ) 
A PRELIMINARY Notice By ARNOLD GRAF, Pu. D. 
In recent years the question whether the Hirudinea possessed 
funnels or not has been again brought forward by H. Bolsius. 
His investigations seemed to prove that there were no funnels 
in any genus of Hirudinea. 
Since then the criticism of Bourne appeared, in which he re- 
jects the investigations of Bolsius. I agree in most of the 
points with Bourne. 
I have been working about two years on leeches, and in my 
first paper upon the excretory organs of Nephelis, I pointed out 
that most of the assertions of Bolsius were due to misinterpre- 
tation. Since then I had the satisfaction of getting some very 
= 
good series of Clepsine and Nephelis, in which I could see the 
