icîth some Remm-ks on the Natitre of the Spoiigiœ ISIarinee. 397 



thin, diaphanous, and colourless filaments, to spring ffoin the surface of the 

 SpongUla Jiiiviat'ilis, when kept even in fresh water, and to increase in length. 

 This latter fact I consider as the better accounting for the presence of those 

 filaments; and I entertain in my own mind little, if any, doubt that the fila- 

 ments of the Conferva (or OscUlatovia probably) which I have so repeatedly 

 examined under the microscope, and seen attached so often to that Sponge, 

 are in reality the " filamens flagelliformes" spoken of by Dnjardin, and that 

 the motions of that Conferva or OscUlaturia in the liquid, easily and most na- 

 turally explain the cause of "les filamens agités sur le contour de certains 

 fragmens" of the SpongUla lacustris. Wlierefore I think no analogy can be 

 drawn from these filaments, as this author has done in the following passage, 

 " De ces parcelles le plus extérieures sont, en outre, munies de longs filamens 

 fiagelliformes, comme les Monades, les Goniiim, les l'olvox, &c. pour déter- 

 miner à la surface le déplacement de l'eau et j ar suite les courans dans les 

 oscules, d'où résulte un contact plus multiplié de la partie vivante avec le 

 liquide, qui lui fournit des matériaux d'assimilation*," with the organs of 

 motion of those Infusoria ; because the former do not at all resemble, as far as 

 I can learn from the researches of Dr. Ehrenberg, the latter, which are only 

 cilia or mere seta?, anil not what could with any propriety be termed " very 

 long, whiplike filaments, of an extreme slenderness." 



And in the thirtl place, I cannot from M. Dujardin's observations under- 

 stand that the "parcelles amorphes," by a grouping or aggregation of which 

 he supposes the mass of the Sponge itself to be formed, are in any respect 

 more " analogues aux Amibes^' — which Amœhœ, Ehrenberg tells us, are or- 

 ganized animalcula, possessing at least a mouth and gastric sacs, — than are 

 similar portions of many of the gelatinous structures of the Algœ, or even of 

 certain kinds of the Fungi. 



Moreover, it is clear that no good argument in support of the animality of 

 the Spongillœ can be brought forward from their smell ; for I have found this, 

 when the specimen is quite fresh and immersed in pure water, to be rather 

 pleasant than otherwise, but on the decay of the gelatinous portion it cer- 

 tainly is powerful and offensive ; though I am sure that very much of its 

 disagreeableness arises from the death and putrescence of some parasitical 



* See Annales des Sciences Naturelles, Seconde Série (Zoologie), torn. x. p. 10. 



