OF THE NATURE OF SPONGES. 63 



view of the animal or live jelly.* Subsequent researches 

 into the nature of the fi-esh-water sponge having convinced 

 him of his error so far as it was concerned, he began to ima- 

 gine " that it might possibly be quite a different substance 

 from the sea-sponges ; and if so, these latter might be yet 

 esteemed of a true annual nature. However," he conti- 

 nues, " still more recent and minute comparisons of many 

 of these, as preserved in several collections, with the Spon- 

 gilla, have compelled me to abandon that idea ; for I can- 

 not find any more solid ground for it, than for holding that 

 one genus of the Fungi, as Merulius, belongs to a per- 

 fectly distinct division of natiu'e, from another genus of the 

 same Order, for instance Ayaricus ; and as all who should 

 behold them would immediately and unhesitatingly ac- 

 knowledge both the one and the other to be a true mush- 

 room or Fungus ; so we are equally obliged to admit that 

 the Spongia and Spojigilla are in fact both real sponges : 

 indeed there scarcely is even so much as a generic differ- 

 ence between them ; and in this, with the earlier natm'a- 

 lists Dr Fleming coincides, for he places both kinds in one 

 and the same genus, Halichondria.'''' 



" Both the fresh-water and the sea sponges are fuiniished 

 with a skeleton of fibres interlacing, crossing, and anasto- 

 mosing with themselves ; generally also strengthened with 

 those singularly crystallized particles termed spicula ; with 

 a parenchymatous soft portion or jelly ; with a fine and 

 transparent enveloping membrane ; with numerous minute 

 pores ; and frequently with larger orifices or oscules, which 

 are more sparingly and irregularly dispersed over their 

 surfaces ; with passages or canals communicating through 



* Natural History of Stocktou-on- Tees, p. .3S. Storktou, I8'27. 



