OF THE NATURE OF SPONGES. 33 



zoophyte, — the last link of the long chain of animals, fi-om 

 which natm-e stept, without visible effort or leap, to the 

 fungous and algous tribes of the vegetable kingdom. He 

 thought it probable that they imbibed their nutriment by 

 the pores or cavities alone, in which the offices of a mouth 

 and stomach might be perhaps combined, as they are in the 

 pores in the roots of terrestrial plants, and in the superfi- 

 cial pores of the algae or sea-weeds ;* but he acknowledges 

 that nothing certain had been ascertained of their mode of 

 growth and propagation. 



In the 12th edition of the " Systema," published in 1767, 

 Linnaeus, following the advice of Ellis and the example of 

 Pallas, arranged the sponges amongst animal zoophytes, 

 but, from the position which they occupy, it appears that 

 he did not consider them the very lowest of their race. 

 His definition of the genus is : — " Spongia. Flores. (Fo- 

 raminibus respirat aquam.) Stirps radicata, pilis contexta, 

 flexilis, bibula."t 



From this date the animality of sponges was generally 

 assumed, and the ideas of Ellis regarding their structure 

 and functions were as generally admitted, but not alto- 

 gether without the protest of a small minority. Spallan- 

 zani was the most celebrated of these ; and, from Lamou- 

 roux and Mr Gray,:}: we learn that he was joined in his 



• " Spongiarum, quani reliquis omnibus Zoophytis, miiltosimpliciorem 

 atque imperfectiorem esse fabricam cum Ellisio sentio. Eoque magis 

 ad vegetabilia accedunt, quam reliqua hiijus ordinis genera. Cliymicis 

 etiam principiis paulo similiores plantis deprehenduntur. Credibile 

 est pom solis aut cavernulis nutrimentum recipere Spongias easque ca- 

 vernulas oris simul et ventriculi vices genere, uti pori radicum in plan- 

 tis terrenis et superficiales in Algis." Elench. Zoopli. .376. 



t Syst. Nat. i. p. 1296. 



X Hist. Corall. I'lcx. p. J 1 ; and Zoological Journal, i. p. 47 and 49. 



C 



