38 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
in which he discusses their characters in the greatest detail. We have 
only space for the conclusions which he summarizes in two phylogenetic 
tables ; he thinks it almost certain that the primitive ancestor was 
marine. 
A B 
Sexual Dimorphism of Copepoda Ascidiicola.* — M. E. Canu 
points out that there are very considerable differences between the 
sexes in these Crustacea ; the males have rarely been observed, and when 
they have they have ordinarily been described as distinct species. It is 
necessary to follow the various stages before defining species. He gives 
a special account of Enterocola fulgens, which is often found on 
Polyclinum succineum. 
Test-gland of Freshwater Copepoda.f — M. J. Richard has a pre- 
liminary notice of his researches on the so-called test-gland of Copepods, 
in which he makes some additions to the knowledge acquired for us by 
Prof. Claus. He has examined the organ in a number of forms. 
Polar Bodies of Balanus.J — Hr. B. Solger states that he has lately 
been able to observe the formation of both polar globules in a large 
number of eggs of Balanus imjorovisus. During the process of constric- 
tion of the second the first lay on the outer surface of the egg-membrane. 
An ovarian lamella was fixed in chrom-acetic acid and cut into a series 
of sections. After staining with hsematoxylin a large number of eggs 
exhibited, near the blunt pole, a well-marked spindle, which on account 
of its size, appeared to be the first. Further details are given, and it is 
* Comptes Rendus, cxi. (1890) pp. 757-9. 
t Bull. Soc. Zool., xv. (1890) pp. 113-8. 
j Zool. Anzeig., xiii. (1890) pp. 607-9. 
