ZOOLOGY AND BOTANY, MICROSCOPY, ETC. o7 
nerve-collar are formed by five pairs of ganglionic centres which innervate 
the five pairs of foot-jaws. The hinder part of the nerve-collar is 
formed by the very close fusion of two pairs of ganglionic centres, the 
second of which innervates the operculum. 
e. Crustacea. 
Amoeboid Cells in Crab’s Blood.* — Prof. G. Cattaneo describes 
the granular and hyaline cells in the blood of Carcinus msenas. The 
two kinds of cells are simply different physiological states of the same 
set of elements. The normal form is that with localized polar or 
bipolar pseudopodia, but this may degenerate into a radiating amoeboid 
phase, or the amoeboid cells may unite abnormally in plasmodia. The 
various phases are compared with those of Myxomycetes. With some 
difficulty Cattaneo was able to demonstrate that the cells may absorb 
particles in phagocytic fashion. He describes their behaviour in water, 
when undergoing desiccation, in relation to oxygen, carbonic acid, and 
chemical reagents, and his results are like those of Graber and From- 
mann. A ciliated Infusorian, Anophrys maggii, is sometimes an abundant 
parasite in the blood. 
Excretory Apparatus of Palinurus, Gebia, and Crangon.j — M. P. 
Marchal, in continuation J of his studies on the excretory apparatus of 
Crustacea, describes those of Palinurus vulgaris and Crangon vulgaris. 
With regard to the internal structure of the organ in Gebia we may note 
that there is a sacculus with a central cavity from which are given 
off numerous ramifications which pass into the reticulated tissue of 
the surrounding labyrinth ; this tissue is very dense and the glandular 
lacunae in it are extremely numerous. The clear portion is formed 
by a less dense glandular reticulum, and the spaces become pro- 
gressively larger near the excretory tubercle, with the orifice of which 
one space communicates by means of a fine canaliculus. Crangon has, 
like Palsemon , a large unpaired bladder lying above the stomach ; 
it has numerous lobes which make their way between the different 
organs. In a preceding notice the author spoke of the mobile piece 
which carries the excretory orifice in Maia as representing the excretory 
tubercle of the Macrura, but he is now convinced that it corresponds to 
the whole joint which carries this tubercle. In other words, it is the 
homologue of the first joint of the antennas of the Macrura. 
Palsemonetes varians.§ — Mr. W. F. R. Weldon has examined nearly 
a thousand specimens of Palsemonetes varians at Plymouth, and finds a 
considerable amount of variation in the characters of the rostrum. 
There is at Plymouth a race which approximates in its habits to the 
races of Southern Europe, but in its development, at least, completely 
resembles those northern forms from which it is probably descended. 
Three Subterranean Gammarid8e.|| — Dr. A. Wzesniowski has 
published a German translation of his Polish essay on these Amphipods, 
* Atti Soc. Ital. Sci. Nat., xxxi. (1889) pp. 231-66 (1 pi.). 
f Comptes Rendus, cxi. (1890) pp. 580-2. % See this Journal, 1890, p. 719, 
§ Journ. Marine Biol. Assoc., i. (1890) pp. 459-61. 
If Zeitschr. f. Wiss. Zool., 1. (1890) pp. 600-724 (6 pis.). 
