ON SOME PHENOMENA OF COALESCENCE AND 

 REGENERATION IN SPONGES^ 



BY 



H. V. WILSON 



With Four Figures 



I 



In a recent communication I described some degenerative and 

 regenerative phenomena in sponges and pointed out that a knowl- 

 edge of these powers made it possible for us to grow sponges in 

 a new way. The gist of the matter is that siHcious sponges when 

 kept m confinement under proper conditions degenerate in such 

 a manner that while the bulk of the sponge dies, the cells in certain 

 regions become aggregated to form lumps of undifferentiated 

 tissue. Such lumps or plasmodial masses, which may be exceed- 

 ingly abundant, are often of a rounded shape resembling gem- 

 mules, more especially the simpler gemmules of marine sponges 

 (Chahna, e. g.), and were shown to possess in at least one form 

 (Stylotella) full regenerative power. When isolated they grow 

 and differentiate producing perfect sponges. I described more- 

 over a simple method by which plasmodial masses of the same 

 appearance could be directly produced (in Microciona). The 

 sponge was kept in aquarium until the degenerative process had 

 begun. It was then teased with needles so as to hberate cells and 

 cell agglomerates. These were brought together with the result 

 that they fused and formed masses similar in appearance to those 

 produced in this species when the sponge remains quietly in 

 aquarium. At the time I was forced to leave it an open question 

 whether the masses of teased tissue were able to regenerate the 

 sponge body. 



During the past summer's work at the Beaufort Laboratory^ 



1 Published with the permission of Hon. Geo. M. Bowers, U. S. Commissioner of Fisheries. 

 n am indebted to the director of the station, Mr. H. D. Aller, for his kindly aid in supplying all 

 facilities needed in the course of my investigation. 



The Journal of Experimental Zoology, vol. v, no. 2. 



