OF THE NATURE OF SPONGES. 31 



ever, believed the sponges to be plants ; and the proof which 

 others saw, in liis observation, of their zoophytical charac- 

 ter, was deemed inconclusive by Valisnerius, who weaken- 

 ed its force and bearing by comparing the alleged move- 

 ments to those of the sensitive plant.* Peyssonel's disco- 

 very of the animality of zoophytes in general, followed quick 

 on that of Marsigli ; and when the truth of this was ge- 

 nerally recognized, after the confirmation it received, about 

 the middle of the century, from Trembley, Donati, Jus- 

 sieu and Ellis, there was rather too much eagerness among 

 zoologists to adopt the sponges also, and to restore them to 

 the rank they held in the writings of antiquity, for the facts 

 on which tliis restoration was rested were of a much less sa- 

 tisfactory description than those which proved the animal 

 nature of the Hydra, the Sertularise and Alcyonia. 



Donati was led, by the researches he had made into the 

 productions of the Adi-iatic, to regard the sponges as an 

 order of Plant-animals, — a class of beings pertaining to 

 neither kingdom of organized matter, but connecting them 

 by embodying their essential attributes ; and among which 

 were some species ( Tethja) that had even some relationship 

 with minerals.! From observations made on the American 

 coast, Peyssonel was, on the contrary, induced to believe 

 that sponges were fabricated by certain worms which are 

 frequently met with in their sinuosities and pores. This 

 opinion was disproved by Ellis,:}: who shewed that Aristotle 



• Eplierneiid. Acad. Leopold, cent. x. p. 345. 



f Delia Storia Naturale Marina dell' Adriatico, p. Ivii. c. p. Ixiii. 

 Venezia, 1750. 



\ " This kind of insect, which harbours in sponges, I have seen ; but 

 sponges have no such animals to give them life, and to form them." El- 

 lis in Lin. Corresp. i- p. 180. 



