434 HISTORY OF ZOOPHYTOLOGY. 



tions of polypes, the zoologist who retains them in his province 

 must contend that they are individually animals, an opinion 

 to which I cannot assent, seeing that they have no animal 

 structure or individual organs, and exhibit no one function 

 usually sujjposed 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 involuntary, — their nutriment is elaborated 

 in no appropriated digestive sac, — and, like cryptogamous vege- 

 tables or algse, they usually grow and ramify in forms deter- 

 mined by local circumstances, and if they present some pecu- 

 liarities 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.''^ 



* The same reasons induced Dutrochet to come to the same conclusion, (Ann. des 

 So. Nat. n. s. x. p. 12 ;) and the definition of a vegetable given by one of the first 

 botanists on the Continent — " sensililitate, voluniate, et motu propria destittita" — will 

 certainly include both corallines and sponges. See Macleaj^'s Hor. Entom. p. 197. 

 According to Deshayes, (Traite Elem. de Conchyliologie, i. p. 9,) irritability — "Pirri- 

 tabilite manifestee par le mouvement " — is the essential characteristic of animals, — a 

 definition which still excludes sponges and corallines from amongst them. 



Professor Owen says, " that, if a line could be drawn between the animal and vege- 

 table kingdoms, the sponges should be placed upon the vegetable side of that line. 

 Locomotion could be no proof of animality ; for it was well known that the sporules of 

 some cryptogamic plants possessed very perfectly the power of motion." — Lancet, 

 No. 871, p. 225. 



