462 
C(ELENTERATA. 
of the Eudoxia as parts of the same individual Medusa, from their making 
their appearance independently of each other. The 2nd polypite from the 
end is better developed ; but only the 3rd is a perfect Eudoxia, with scale 
*&c. The last (oldest) two polypites are probably destroyed with the succes- 
sive dissolving of the polypite into distinct Eudoxice. This is ^ spontaneous 
act, originating in a reabsorption of the intermediate portion of the stem, 
which afterwards forms the ‘juice-reservoir ’ of the EudoxiaAieW. In the 2nd 
part of his dissertation Muller records his observations on the fecundation of 
the egg of the Siphonophora, describing especially the “ micropyle ”-like struc- 
tures of the surrounding parts in Hippopodius, and the active contact of the 
transformed a.noeboid spermatozoa with the germinal spot, without penetra- 
tion or any other visible mixing of the contents. He adopts the “ contact ” 
theory of fecundation. 
13. Panceri, P. 1. Etudes sur la phosphorescence des aiii- 
maux marins. 2. Du siege du mouvement lumineux dans 
les Meduses. Ann. Sc. Nat (5) xvi. 8, pp. 4-12, from 
Rend. Acc. Nap. viii. (1871). 
Some Medusce are not luminous ; in others the luminosity is restricted to 
the marginal bulbs at the base of the tentacles ; in others, again, to the 
ovaries or the radial vessels j in PcUu/ia noctiluca the whole external surlhce 
is luminous 5 in Cunina moneta only the tentacles aud the velum. The au- 
thor’s observations bear especially on these two Acalephs ; he ascertained 
that the seat of the luminosity is in the epithelial cells, and more espe- 
cially in the fat-like substance deposited in these cells, under the appear- 
ance of delicate, yellowish, highly refractile granulations. 
14. Rotch, W. D. On a new genus and species of Hydroid 
Zoophytes. Ann. N. H. (4) x. pp. 126 & 127. 
15. Spaonolini, a. Catalogo degli Acalefi del golfo di Napoli. 
Atti Soc. Ital. xiv. 3 (1871), pp. 83. 
Anatomy ^c. 
Kleinenberg (9), in his investigation of the histological structure and 
development of the freshwater polype, states that the body is composed of : — 
an entoderm, consisting of a single layer of cells, some of them flagellate, on 
which devolve all the nutritive (digestive, excretory, &c.) functions ; and an 
ectoderm, consisting chiefly of a layer of larger cells, produced into delicate 
branching fibres, which take a longitudinal direction and form, connected by 
some homogeneous substance, — a contiguous muscular plate separating the 
ectoderm from the entoderm. These productions of the ectodermal cells are 
considered to fulfil the functions of muscles, and the cells themselves those 
of a nervous system ; they are therefore termed “ neuromuscular cells.” 
The intervals between their proximal parts are filled up by many small 
“ interstitial cells,” wanting only in the foot-disk, but profusely developed in 
the tentacles j they give origin to the ‘‘ urticating capsules and the sper- 
maries and ovaries are formed through the exuberant growth of parts of this 
tissue — the spermaries first, 2-20 on the oral part of the body, below the ten- 
tacles, the ovaries on its lower port ; when these are present in greater number 
