PROGRESS OF MICROSCOPICAL SCIENCE, 251 
term he applies to (gastrula-like) organisms formed of two kinds of 
cellules, some ectodermic, others endodermic, in which the endoderm 
is formed by invagination. He calls Planulades, those hypothetical 
Mesozoa which are formed from a many-celled sphere constituted like 
a Magosphera (Haeckel) and in which the two cellular layers are 
developed by delamination. He therefore divides the animal kingdom 
into three primary groups, that is, the Protozoa, the Mesozoa, and the 
Metazoa. i 
A curious New Sponge, Kallispongia.—Professor E. Perceval Wright 
describes * a beautiful little sponge found growing on the fronds of 
some species of red seaweeds from the coasts of Australia. _ The 
largest specimens measure not three millimeters in height. The 
sponge consists of three distinct and well-marked portions: firstly, a 
small basal disk; secondly, an elongated stem, on the summit -of 
which expands the third portion, or capitulum. The disk is button- 
shaped, flat, and is formed of an irregular horny framework, twice to 
three times as broad as the stem. The stem varies in height, and 
presents the appearance, in some cases, of a series of margined rings, 
some twenty in number, fastened together one on the top of the other; 
in others the margins of the rings will be more prominent, and the 
bodies of the rings will be, as it were, more deeply sunk. In both 
these cases the horny framework is of a more or less evenly latticed 
character, the longitudinal lines of the lattice being very prominent. 
The head portion, in its natural state, probably presents a more or less 
spherical form, perhaps slightly flattened on the summit, with an in- 
dication of being divided into four nearly equal parts, the open space 
between these leading into the body-cavity of the sponge. In some of 
the specimens the head portion nearest to the stem seems to have been 
formed of a somewhat denser framework than the upper portion, so 
that while being pressed this upper portion has been fractured across. 
The framework here is of a densely reticulated kind, in appearance 
reminding one of the reticulated network of the intracapsular sarcode 
in Thalassolampe, or of the tissues met with in some Echinoderms. 
This sponge has been called Kallispongia Archeri. The wonderful 
mimetic resemblance which it bears to some Crinoid forms can 
scarcely be overlooked. Leaving the texture and composition of the 
skeleton mass for the moment out of view, and simply looking at its 
outline—the circular disk-like base, the stem—the profile of which is 
absolutely the same, except as to size, as that of the pentacrinoid stage 
of Antedon rosaceus, and the slightly cleft head, the resemblance is 
very great. 
The Microscopic Anatomy of Vaccination.—Messrs. Braidwood and 
Vacher have published a very lengthy report on this subject in the 
‘British Medical Journal.’ In this they state the following con- 
clusions :—a. The principal local changes excited by the vaccine 
contagium affect the rete mucosum, and consequently the hair- 
follicles. 6b. They consist in corpuscular infiltration of this tissue. 
c. The corpuscles to be most distinctly seen during the earlier days 
* ¢ Proc. R. Irish Acad.’ vol. ii. ser. 2, part 7. 
