1894.] Zoology. 1041 
ZOOLOGY. 
Terminology of the Nerve Cell.— Fish attempts! to avoid some 
of the confused terminology of Neurology by proposing a consistent 
nomenclature, adopting to some extent existing terms. "Thus he would 
callthe entire nerve cell, with its appendages, neurocyte; the axis cyl- 
inder prolongation ; neurite; the other processes dendrites, and the neu- 
roglia cell, spongioeyte. Nerve cells would then be dendritic or aden- 
dritic, mono-or dineuritie, etc., according to the number and character 
of the processes concerned. 
Structure of Clepsine.—Oka has attempted" the solution of some 
of the problems of Hirudinean anatomy. After some remarks on ex- 
ternal morphology, he takes up in succession the body cavity, blood 
vessels, nephridia and the systematic position of these animals. The 
text is rendered much more easy of comprehension from the recon- 
structions on the plates. Oka recognizes in the lacuns of the body 
the true celom which is broken up into a large number of anastomos- 
ing cavities, in which may be recognized the following principal regions: 
in the middle of the body, a median dorsal and a median ventral lacuna, 
in each of which run blood vessels. In front and behind these fuse 
into a “median " lacuna. These lacune are connected by short canals 
witha plicated “ zwischen] ," which runs the length of the body 
on either side, and this in turn by segmentally arranged tubes with a 
lateral lacuna on either side. These various spaces are also connected 
with a subepidermal system of lacunæ, the principal canals of which 
correspond to the annuli of the external surface. In the blood vascu- 
lar system, which is cut off completely from the lacunar cavities, seg- 
mentation has largely disappeared. In but few regions can even the 
most remote resemblance to a segmental arrangement of vessels be 
traced, although the dorsal vessel shows segmental enlargements. The 
nephridia are described at length, the account confirming and supple- 
menting the descriptions of Whitman, Bourne and others, and disagree- 
ing in toto with those of Bolsius, except in that they confirm the latter 
in the description of an ectodermal terminal portion. 
In conclusion, Oka thinks the Hirudinei nearest the Oligoch:etes, 
basing this view upon chiefly three factors: (1) the existence of a seg- 
! Jour. Comp. Neurology, iv, 1894. 
? Zeitschr. wiss. Zool., lviii, 1894. 
