$. 
3 
| 
; apparent. 
FORAMINIFERA. 341 
the spiral form, as the Textularia, &c., the same structure is 
Whatever the form of the body, the filaments always con- 
_ sist of a colourless transparent matter ; they are capable of 
being elongated to six times the diniones of the shell. They 
_ often divide and subdivide, so as to appear branched ; and 
though alike in form in the different genera, vary toon 
in their position. In some species they form a bundle which 
issues from a single aperture, and is withdrawn into the 
same by contraction ; in others, the filaments project only 
through each of the pores in that portion of the,shell which 
_ covers the last segment : in many they issue from both the 
_ large aperture and the foramina. These filaments or pseudo- 
podia fulfil in these animals the functions of the numerous 
tentacula in the Star-fishes ; serving as instruments of loco- 
- motion and attachment. 
Neither organs of nutriment nor of reproduction have 
been discovered. In the genera having one large aperture 
from which the filaments issue and retract, we can conceive 
nutriment to be absorbed by that opening; but this cannot 
be the case in the species which have the last cell closed up ; 
in these the filaments issuing through the foramina are 
_ probably also organs of nutrition. M. D’Orbigny considers 
the Foraminifera as constituting a distinct class in zoology ; 
though less complicated than the Echinoderms and the 
Polypifera in their internal organization, they have the mode 
of locomotion of the first ; while by their free, individual exist- 
ence, they are more advanced in the scale of being than the 
aggregated and immovably fixed animals of the latter class. 
But though I consider the animal of the Foraminifera as 
single, and the additional lobes, or segments, as the con- 
tinuous growth of the same individual, I must state that 
Some eminent naturalists regard the entire structure as a — 
series of distinct individuals, developed by gemmation from 
the first formed segment, like the clusters of the compound 
