428 Mr. H. J. Carter on the Reproduction of Sponges. 



the intercellular plasma wliicli exists between the globular 

 cells (Annals, 1857, vol. xx. p. 26). 



The presence of a capsular covering to the ovum in Spon- 

 gtlla, and its absence in the Tethyce and the marine sponges 

 generally, is explained by the drought to which the former 

 may be exposed during subsidence of the fresh water in 

 which it is growing. Thus the masses of Hpongilla in the 

 tanks of Bombay become uncovered and perfectly dry for 

 several months in the year — a contingency to which the 

 marine sponges can never be exposed ; and hence the capsule, 

 instead of being a protection to them, would be in the way of 

 the full development of the ovum, which goes on uninter- 

 ruptedly from the beginning to the end, when it is ejected 

 into the water in a state of comparative maturity. The con- 

 tents of the ovum of Spongilla^ on the other hand, do not 

 reach this state until they have emerged from the capsule and 

 become developed into the young Spongilla. 



Of course, in a new field like this, to which I have now and 

 then turned my attention for the last twenty years, my views 

 progressively have been somewhat modified — and yet not 

 much, as will be seen by my " Description of the Fresh- 

 water Sponges of Bombay," first published in the 'Journal of 

 the Asiatic Society of Bombay,' in 1849, and subsequently 

 reprinted in the ' Annals ' of the same year (I. c). 



In describing the development of the young Spongilla from 

 the seed-like body in the paper just mentioned, it may be ob- 

 served, at p. 87, that I mention an " intercellular substance," 

 or " semitransparent mucilage," which forms the " bond of 

 union between the cells " of Spongilla^ that it possesses a 

 power of polymorphism " independently of the sponge-cells, 

 and presents contracting vesicles." All this, too, is figured in 

 the illustrations (pi. 4. fig. 2). Finally, at p. 95 is the fol- 

 lowing sentence : — " My impression, however, is, that both 

 the horny skeleton and its spicules are formed in the inter- 

 cellular substance, and not within the cells." This is Hackel's 

 view in 1870 ; and for this " intercellular substance " he pro- 

 poses the name of " sarcodine" or " syncytium "(Annals, 1870, 

 vol. V. pp. 112 & 113, " On the Organization of Sponges &c.," 

 translated). No allusion whatever is made to my notice of the 

 same substance &c. in 1849, which probably would have been 

 the case had this naturalist read all that had been written on 

 the subject previously to writing himself. How unlike the old 

 Salmasiuses and Bocharts, &c., who read every thing on their 

 subject and acknowledged it ! Has not the age for these 

 master minds passed away amidst the growing desire to avoid 

 every thing that gives extra trouble, even though it may entail 

 inferior work? 



