PROGRESS OF MICROSCOPICAL SCIENCE. 
261 
then showing themselves successively as an internal layer with con- 
centric fibres, and an external with longitudinal. (5) Lastly, a flat- 
tened epithelium, the peritoneal serous epithelium. The author 
gives a very good plate, which illustrates these layers with dis- 
tinctness. 
The Mode in which the Young of the New Zealand Astacoides attach 
themselves to the Mother. — In a paper in the ' Annals of Natural 
History ' (October 1876), Mr. J. Wood-Mason describes an interest- 
ing structure, by means of which the young of the Now Zealand cray- 
fish attach themselves to the mother. Indeed, it strikes us that the 
idea of the young being attached at all is decidedly a novel fact. 
Mr. Mason gives a magnified figure of one of the limbs of the 
young Astacoides, which shows us that at the extremity it is furnished 
with a peculiar hook-like process. This so firmly sticks in the 
mother, that Mr. Mason had to pull the young animal away without 
its limb in order to disengage it. 
Deep-sea Sponges and their Spicules. — Mr. H. J. Carter, F.E.S., 
continues his valuable papers on this subject in the ' Annals of 
Natural History.' In the number for October he describes and 
figures many points in their microscopic anatomy. His paper is not 
completed, but is to be continued. 
A New Hydroid Polyp Tiarella singularis. — Herr F. E. Schultze 
describes a new polyp, which he recently discovered in the Mediter- 
ranean, and which he calls as above. He figures it as a whole, much 
enlarged, and he gives a plate illustrative of its microscopic anatomy. 
He describes minutely the perisarc, coenosaix, and hydranth, and gives 
full details as to its reproductive apparatus.* 
Vascular Networks of the Eye in Vertebrates. — M. Beauregard has 
certainly exhausted this subject in the splendid memoir he has pub- 
lished in the ' Annales des Sciences Naturelles.' "j* In a paper of 158 
pages, with six admirable plates, he goes into the structure of these 
apparatus as they present themselves in birds, reptiles, batrachians, 
and fishes. Nay more, for he goes into the developmental stages of 
each. The paper is of extreme length, and the author deals fully in 
the preceding part with the views of many of his predecessors in the 
field. The most novel part of the work is that in which he describes 
how he applied the ophthalmoscope even to the eyes of fishes, and the 
means by which he kept up artificial respiration whilst he was ob- 
serving the structures. In some cases this lasted for hours. 
The Development of the Crustacean Embryo. — The ' Proceedings of 
the Eoyal Society' (No. 168) contains an abstract of a capital paper 
by our very best English authority on this subject. Mr. C. Spenco 
Bate, F.E.S., who is its author, states that although the general forms 
of several genera of Podophthalmous Crustacea are known, yet the 
details of their structure have been so unsatisfactorily figured and 
described, that the value and importance of hereditary elements are 
incapable of being studied and aj^preciated. 
* Vkle Siebold und Kolliker's ' Zietsclirift,' 27tli Baud, 3 Heft, 1876. 
t Tom. iv., No. I to 3. 
