EXPERIMENTS ON SPONGES. 121 



from other statements he made it is certain that he consid- 

 ered its place as between the animal and vegetable. Some 

 modern naturalists have placed sponges among marine vege- 

 tables, and their appearance, if one casually looks at them, 

 would seem to justify such an opinion; but the researches 

 of Mr. Ellis, a merchant of London, who made similar 

 branches of natural history a particular pursuit, gave addi- 

 tional interest to this case. In the course of his microscopic 

 investigations, he was astonished at discovering that sponges 

 possessed a system of pores and vessels, in which sea-water 

 passed with all the appearance of the regular circulation of 

 fluids in animal bodies, and a seeming purpose of conveying 

 small minute animals to itself for food. 



Afterward, Dr. Grant gave the result of his experiments 

 on the same subject. The account is so interesting that we 

 will give it in his own words. ** Having placed a portion of 

 sponge in a watch-glass with some sea-water, I beheld for 

 the first time the splendid spectacle of this living fountain 

 vomiting forth from a circular cavity an impetuous torrent 

 of liquid matter, and hurling along in rapid succession opaque 

 masses, which it strewed everywhere around. The beauty 

 and novelty of such a scene in the animal kingdom long ar- 

 rested my attention ; but after twenty-five minutes of con- 

 stant observation, I was obliged to withdraw my eye from 

 fatigue, without having seen the torrent for an instant change 

 its direction or diminish the rapidity of its course. In ob- 

 serving another species, I placed two entire portions of this 

 together 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 ejected. I placed one of them 

 in a shallow vessel, and just covered its surface and highest 

 orifice with water. On strewing some powdered chalk on 

 the surface of the water, the currents were visible to a great 

 distance : and on placing some pieces of cork or dry paper 



