Natural History of British Zoophytes. 2*29 
buminous or calcareous sheath, appropriated solely to support or pro- 
tection.* 
But although I agree with the advocates of the animality of zoo- 
phytes in general, I cannot go the length of Ellis in considering it 
proved that sponges and corallines belong to the same class. Ellis, 
we have seen, knew that no polypes were to be found in sponge, and 
their existence in the pores of corallines was inferred merely from the 
structure of these and their chemical composition. They have been 
examined by subsequent naturalists fully competent to the task, and 
under the most favourable circumstances,- in particular by Cavolini 
and Schweigger, and the result has been a conviction that these 
productions are truly apolypous. Now this fact, in my opinion, 
determines the point, for if they are not the productions of polypes, 
the zoologist who retains them in his province must contend that 
they are individually animals, an opinion to which I cannot as- 
sent, seeing that they have no animal structure or individual organs, 
and exhibit no one function usually supposed to be characteristic of 
that kingdom. Like vegetables they are permanently fixed, like 
vegetables they are non-irritable, their movements, like those of 
vegetables, are extrinsical and in voluntary, like cry ptogamous vege- 
tables or algae they usually grow and ramify in forms determined by 
local circumstances, and if they present some peculiarities in the 
mode of the imbibition of their food and in their secretions, yet even 
in these they evince a nearer affinity to plants than to any animal 
whatever. 
II. ON THE STRUCTURE AND FUNCTIONS OF THE POLYPES 
ABSTRACTEDLY CONSIDERED. 
On the continent the term Zoophyte has of late been used in a 
very extensive sense, so as to include every animal which exhibits 
a circular disposition of parts radiating from a common centre, and 
many also in which this character is little or not at all obvious. In 
this country the word has never been so employed excepting in trans- 
lations from a foreign language : no English writer ever thinks of 
calling an intestinal worm, or a sea-jelly, or a star-fish, or even the 
* I do not enter into the question whether the Confervse are real animals or 
not, because, whatever conclusion we might adopt, they would not come within 
our definition of a zoophyte or polype, since they assuredly have neither mouth, 
tentacula, nor stomach. Nor need I discuss the propriety of instituting, with 
Treviranus, a fourth kingdom of animated nature, composed of the zoophytes 
and aquatic cryptogamia, as my object and plan is only to describe what have 
bee;i almost universally considered zoophytes. 
NO. III. Q 
