176 
POPULAR SCIENCE REVIEW. 
Mr. Carter refers in this paper to Professor Clark’s view 
expressed in 1868, that “the monociliated sponge cell is a dis- 
tinct flagellated infusorium,” not related to the rhizopoda ; and 
that a sponge is a colony of such infusorians ; and he observes 
that while he cannot altogether endorse it, he did not then 
wish to dispute it. 
In a later paper (“Annals,” July 1871) he refers to this 
passage, and adds, “ it is with great pleasure that I can now 
endorse them — that is, that I am now able to confirm all that 
Professor James Clark has stated of the flagellated sponge-cell 
in the valuable memoir to which I have referred.” 
Examining specimens of Grantia compressa he found that 
the “ ear-like points,” mentioned in a passage we have cited, 
noticed in spongilla were, as Clark had suspected, right and 
left profiles of the cylindrical collar described by him. 
Feeding Grantia compressa with indigo and then tearing it 
to pieces, he found the collared monociliated cells more or 
less filled with indigo, and in entire vitality.” 
Mr. Carter, up to the date of this paper, is disposed to regard 
the sponge-cell as something sui generis , and neither an amaeba 
nor a flagellate infusorian. He says, “So long as the collar of 
the sponge-cell is present with the cilium, all particles of food 
may go in and out of the body through the collar ; but as every 
part of the sponge-cell is polymorphic, it may put forth 
pseudopodia from one part in particular, or from any part of 
the body, like amseba.” 
Here then is plenty of work for microscopists, and it is 
hoped that students to whom these questions are novel will 
find the preceding remarks smooth their way. 
EXPLANATION OF PLATE LXXXIV. 
Eig. 1. Portion of Spongilla arachnoidea in section x 30. a, the monad 
chamber. 
2. Interior of a monad chamber x 780. 
3. Single monad as seen in profile in monad chamber. Two con- 
tractile vesicles v v. Cylindrical collar c extended to the utmost 
x 1,600. 
4. Sectional view of monad chamber bringing the aperture, and 
monad on the same level into profile, showing their convergence 
towards central space x 780. 
The above from Prof. Clark’s paper, see “Monthly Microscopical 
Journal,” March, 1862. 
5. A, Sponge cell from Grantia compressa. 
b, „ with pseudopodia at fundus of cell. 
c, „ with collar transformed into pseudopodia. 
