ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 335 
supporting, a number of ectoderm-cells leave the epithelium, pass 
inwards and become ganglionic cells. The whole of this nervous 
system disappears soon after the larva becomes fixed, and it is not for 
two or three weeks that an extremely fine nerve-ring appears ; this is 
formed altogether from the ectoderm, and is the nervous system described 
by Ludwig. In the oldest larva? at his disposal the author was unable 
to see the rudiments of the nervous system described by Jickeli and 
Carpenter. 
Aboral Vascular Lacunae in Ophiothricidae.* * * § — Sig. A. Russo 
describes a connection between these lacunae and the stomach in Ophio- 
thrix Jragilis and 0 . echinata . 
New Bilateral Holothurian.f — Prof. E. Perrier describes, under 
the name of Georisia ornata , a Holothurian from the Mozambique. Tt 
has a marked bilateral symmetry, and though small (17 mm. long) 
recalls the Elasipod Psychropotes , ending as it does in a sort of tail. 
The resemblance, however, is altogether external, and Georisia is one of 
the Dendrochirotse, and a member of the subfamily Psolinae. The author 
gives a detailed comparison between Psolus and this new genus, and 
shows that, notwithstanding its peculiar appearances, Georisia is less 
aberrant from the normal Holothurian type even than Psolus. 
Ccelentera. 
Digestion of Ccelentera. :f — Dr. M. Chapeaux has been able to con- 
vince himself that in the siphonophorous forms Apolemia uvaria and 
Diphyes acuminata the endodermic cells are true phagocytes, and that 
they are capable of fusing into a large plasmodium when they require 
to digest bodies which are relatively large. 
The author has investigated the action of the digestive ferments of 
Actiniae on starch, cellulose, chlorophyll, and fats. Starch is converted 
into glucose, but neither cellulose nor chlorophyll are digested ; fats 
undergo emulsion and are broken up, and more rapidly in an acid than 
in a neutral or alkaline medium. As may be supposed, the ferments of 
Actinias are powerless against Algae. Similar statements may be made as 
to the digestive power of Siphonophora and craspedote Medusae. At the 
same time it is not to be supposed that the digestion of Coelentera is ex- 
clusively intracellular in its action ; there is a secretion, though a feeble 
one, of ferments in the gastrovascular cavity in many cases ; in the 
Siphonophora digestion is, without doubt, exclusively intracellular. 
Histology of Ccelentera.§ — Dr. K. C. Schneider has been corrobo- 
rating his conclusions as to cell-structure by a study of Coelenterates. 
His method is to macerate with osmic and acetic acid, and to stain with 
carmine. The forms chiefly studied were Forskalea contorta , Velella 
spirans , Carmarina hastata , Pennaria cavolini, Pilema pulmo, Pelagia 
noctiluca , Alcyonium acaule , Adamsia Rondeletii , Beroe ovata. 
Muscular structures may appear in any region of the cell ; they may 
be basal, epithelial, or central, wholly or partially ensheathed in proto- 
* Zool. Anzeig., xvi. (1893) pp. 76-8 (2 figs.). 
t Coraptes Rendus, cxvi. (1893) pp. 557-60. 
X Bull. Ac. Roy. Belg., lxiii. (1893) pp. 262-6. 
§ Jen. Zeitsclir. f. Naturwiss., xxvii. (1893) pp. 379-462 (7 pis.). 
