with some Remarks on the Nature of the Spongise Marinse. 405 



no irritability or powers of contraction and dilatation, no palpitation, and no 

 sensation whatsoever. 



Surely, then, we cannot any longer esteem these natural substances to be 

 individual animals, or even groups of animals, in which not one organ, or a 

 single function or property peculiar to an animal can be discovered*! And 

 that they are in fact neither the nidus or matrix, nor the fabrication or pro- 

 duction of any animal, the mode in which Professor Grant witnessed their 

 locomotive sporules beginning to germinate, to increase, and to develop 

 themselves after the forms of their parent structures f, must be to all tho- 

 roughly satisfactory. 



It is to me nevertheless a subject not altogether certain, and one worthy of 

 some consideration, in what order of plants the Sponges ought to be included. 



Linnaeus, as it will be remembered, in his Flora Lapponica, edit. 1737? and 

 Flora Suecica, edit. 1745, placed the Spongia lacustris and S.JluviatiUs in his 

 class Cryptogamia, and order Lithophyta ; but in the earlier editions of his 

 Genera Plantarum, and of his Species Plantarum, he distributed both the Sea 

 and Freshwater Sponges in his class Cryptogamia and order Algce. 



In a work of a late date, intitled, "A Natural Arrangement of British 

 Plants," by Mr. S. F. Gray, both the Spongilla and the Sea Sponges are classed 

 in the Fam. 2. Thalassiophyta, which belongs to his Subseries I. Plantce Cel- 

 lulosce Aphyllece'^. 



Professor Link has very recently stated, in the work§ quoted in the begin- 

 ning of this letter, that they should be separated from the Zoophytes and re- 

 placed amongst the Algce. But my own observations lead me to conclude 

 that all the Sponges would be more correctly arranged in an intermediate 

 order between the Algce and the Fungi ; for although they are with some rea- 

 son considered by many naturalists to be allied to certain of the Alga^W, still 



* So must we at length agree with the illustrious Greek naturalist, that the Sponges resemble plants 

 in every respect : 6 Ik (rnoyyos, TtavreXiSs eoiKe toU ^vtoIs. Aristot. Hist, de Animal, lib. viii. s. 3. 



t See Edinb. New Phil. Joum. for 1827, p. 137. 



X See vol. i. p. 353 of Mr. Gray's work pubUshed in 1821. 



§ See Annales des Sciences Naturelles, Seconde Serie, torn. ii. (Botanique), p. 328. 



II M. Link however {op. cit. p. 330.) admits, " il est vrai que la structure des Eponges est trfes dif- 

 f6rente de celle des autres Algues ; mais la structure de ces derniferes plantes pr^sente d^j^ des modi- 

 fications si frappantes qu'on ne doit pas s'^tonner d'en rencontrer une de plus." 



