388 



THE MICROSCOPE. 



He ascertained that the water was perpetually sucked into 

 the substance of the sponge, through the minute pores that 

 cover its surface, and again expelled through the larger 

 orifices. His own account is so very interesting, that we 

 cannot resist giving, in his own words, the results arrived 

 at in these investigations : — " Having placed a portion of 

 live sponge {Si^oiiyia coalita, fig. 1, No. 213) in a watch- 







Fig. 213. 

 1. Spongia coalita. 2, Spongla fanicca. 



glass with some sea-water, T beheld for the first time the 

 splendid spectacle of this living fountain, better repre- 

 sented in No. 2, vomiting forth from a circular cavity an 

 impetuous torrent of liquid matter, and hurling along in 

 rapid succession opaque masses, which it strewed every- 

 where around. The beauty and novelty of such a scene 

 in the animal kingdom long arrested my attention ; but 

 after twenty-five minutes of constant observation, I was 

 obliged to withdraw my eye from fatigue, without having 

 seen the torrent for one instant change its direction, or 

 diminish the rapidity of its course. In observing another 

 species {Spongia joanicea), I placed two entire portions of 

 this togetlier in a glass of sea-water, with their orifices 

 opposite to each other at the distance of two inches ; they 

 appeared to the naked eye like two living batteries, and 

 soon covered each other with the materials they ejected. 

 I placed one of them in a shallow vessel, and just covered 



