ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
419 
under a low power of the Microscope. As the granulations multiply 
and increase, pigmentation rapidly becomes more and more marked. 
The nucleus becomes masked, and the different stages which the author 
has already described in the green oyster are here reproduced. 
Brachiopoda. 
Evolution of the Brachiopoda.* — Miss Agnes Crane has a very 
interesting article on this subject, in which she points out that the 
revolution of thought concerning the evolution of these animals is due 
to the recognition of the value of embryology and auxology. She sees 
no reason to change the opinion which she has held for some years that 
where the Brachiopoda go the Polyzoa must follow. A critical account 
is given of the work of various zoologists, and it is urged that one 
stumbling-block in the way of the late Mr. Davidson was his strong 
belief in the immutability of genera. A table too elaborate for us to 
reproduce is given as an attempt to indicate the generic and ordinal 
evolution of the Brachiopoda. 
Bryozoa. 
Nephridium of Endoproctous Polyzoa.j — Prof. A. Oka, who has 
lately J compared the nephridium of the phylactolaematous Polyzoa with 
that of the Endoprocta, basing his remarks on the facts stated by Joliet, 
has lately cut sections of a large number of Endoprocta. He soon found 
out that the description of the organ given by the French naturalist was 
quite correct so far as the external form was concerned, but the mode of 
termination of its free extremity was not correctly made out by him. 
As a matter of fact, the short tubes do not open into the body-cavity at 
all, but end blindly in a large cell with a set of long cilia in a cavity of 
its cell-body, as has already been pointed out by Foetfcinger. It is clear, 
at any rate, that the nephridium of the Endoprocta is constructed 
entirely upon a different plan from that of the phylactolaematous Polyzoa, 
so that the two organs ought by no means to be compared with each 
other ; while the nephridium of the latter is formed by the differentiation 
and folding of the epithelial lining of the body-cavity, and serves as the 
passage of exit for the leucocytes, that of the Endoprocta resembles in 
structure the excretory organs of parenchymatous worms or the pro- 
nephros of certain Molluscan larvae. 
Barerithsia misakiensis.§ — Mr. Asajiro Oka, who has already pub- 
lished a notice on this species in the Japanese language, now favours us 
with an account in one that is more widely understood in Europe. He 
states that each colony is composed of a certain number of individuals in 
various stages of development, which are fixed upon stolons that form 
perfect networks. The stolons are chitinous tubes divided by imperfect 
septa into a number of segments in such a way that the segments that 
carry individuals are always separated by a segment which carries no 
polyps. The animals of every colony are all of one sex only. The 
author makes a critical comparison between this new species and the 
* Geol. Mag., ii. (1895) pp. 65-75 ; 103-16 (2 pis.). 
t Zool. Mag., vii. (1895) pp. 65 and 6. % See this Journal, ante, p. 303. 
§ Zool. Mag., vii. (1895) pp. 76-86 (1 pi.). 
