Group of the “ Physemaria.” 13 
priates for a similar use such foreign particles close at hand 
as may be of a convenient -size and form. Prof. Haeckel 
refuses at present, as in the case of ordinary sponge-structures, 
to recognize in the collar-bearing-monad lining any thing of 
less high organization than a true cellular membrane or tissue, 
comparable to ordinary ciliated epithelium, each collar-bearing 
flagellate monad being, in his opinion, indeed, a mere cell unit. 
That we have here, however, as, judging from their broad 
external characters only, Dr. Bowerbank was the first to decide, 
a true sponge or sarcocryptal Discostomatous Protozoon, there 
cannot be the slightest doubt. It may be further maintained 
that Haliphysema not only represents the simplest sponge- 
type that has yet been discovered, but one in which is found 
epitomized, with but slight modification, the simple monad- 
lined “ ciliated chamber ’”’ or ‘‘ ampullaceous sac ”’ of the more 
complex groups referred to at length on a preceding page. 
The developmental phenomena of the Haliphysemata, as indi- 
cated by Haeckel’s figures and description, are entirely in 
accord with those of the ordinary sponges—compound ciliated 
gemmules, the result of multiple fission, being produced, which 
agree in form and structure with those of Sycon, G'rantia, and 
other sponge-types. The genus Gastrophysema differs from 
Haliphysema only by having several intercommunicating 
internal chambers instead of one, the two, in fact, bearing the 
same relationship to one another that the many-chambered 
foraminiferal genus Nodosaria does to the single-celled Lagena. 
The exceedingly slight and artificial grounds upon which the 
discrimination between two such closely approximating types 
is based, each having necessarily represented the single-cham- 
bered type at one period of its growth, totally unprepares one 
for the account Prof. Haeckel has to render of Gastrophysema 
dithalamium, Haeckel, the simplest and typical representative 
of his second genus. 
Here verily Haeckel has out-Haeckeled Haeckel, and, carried 
away by the ardour of his devotion to the “ Gastrea”’ theory, 
lost all command over the reins of his very fertile imagi- 
nation! Having observed that the ciliated germs and amceboid 
masses (his so-called ova) in the example he examined were, 
as might be rationally anticipated, represented most abundantly 
in the posterior or older-formed of the two chambers, he at 
once takes for granted that the functions of reproduction are 
specially relegated to this chamber, and, with characteristic con- 
fidence in the strength of this bare assumption, bestows upon 
it the title of the “ Bruthéhle oder Uterus.” The upper or 
anterior of the two chambers he invests with the functions of a 
true stomach (‘ Magenhohle’’), while the terminal aperture of 
