with some Remarks on the Nature of the Spongise Marinse. 401 



ing 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 the pores and 

 oscules one with another, along which the water finds a ready course or cir- 

 culation, and affords nutriment to all the inner parts of the masses ; with 

 locomotive sporules ; and in some species with fixed sporidia. 



Concerning these last-mentioned bodies, which I have previously supposed 

 to be sporidia, a fuller notice is here requisite. 



Although M. De Lamarck f has said of the gelatinous bodies or grains that 

 are so numerous in the Spongillae, "que rien de semblable n'a encore 6t6 

 observe dans les v6ritables Eponges," yet they have been recently detected in 

 the Spongice Marince ; for Professor Link has expressly made known in his 

 essay in the Transactions of the Royal Academy of Sciences at Berlin, that 

 M. Ehrenberg told him, that he had seen them (Sporangien;}:) in very many 

 Sponges of the Red Sea. His own words are as follow : " Auch sagt mir 

 Herr Ehrenberg, dass er an mehreren Spongien im Rothen Meere Sporangien 

 bemerkt habe§." 



And indeed these seedlike bodies, little spheres, spherules, or sferette, spo- 

 rangien or sporidia, may be seen well represented in fig. C. at t. c. t. c, and in 

 fig. E. at a. a. a., of Donati's|| Plate VIII., given to illustrate the marine pro- 

 duction called by him " Alcionio primo di Dioscoride," which is synonymous 

 with the Alcyonium cydonium^ of Linnaeus**, and A. cotoneum of Pallasff; 



* As this membrane is subject to some variation, it may be used for a character to distinguish the 

 genera of the Spongice MarituB. f Anim. sans Vert., torn. ii. p. 99, edit. 1816. 



X It is worth while to note, that Link uses in this passage the same word as he had just before 

 done (at p. 120.) when he was describing the similar seedlike bodies (Sporangien) of the Spongilla ; no 

 iincertainty can consequently arise about the exactly identical nature of these bodies. 



§ Abhandlungen der Koniglichen Akademie der Wissenschaften zu Berlin, aus dem Jahre 1830. 

 Berl., 1832, p. 121. 



II See Donati, Storia Naturale Marina dell' Adriatico. Ven., 1750. 



^ The Alcyonium. cydonium of MuUer, which is the Cydonium Mulleri of Fleming and Johnston, is 

 a very different substance, being a true Polypary. Yet Ehrenberg deems the A. cydonium of Midler 

 to be only a young specimen of Alcyonium digitatum of Linnaeus ; and from the figures 3 and 4 in 

 tab. 81. vol. iii. of the Zoologia Danica, edit. Abildgaard (Havn. 1789), it certainly much resembles 

 the early form of that Zoophyte, and before it has developed itself into the usual fingerlike lobes. 



** See Linn. Syst. Nat., edit. 12, p. 1295. tf Pallas, Elench. Zooph., p. 359. 



3 G 2 



