OCEAN LIFE. 7 



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 

 in the slightest degree the rapidity of its course. I continued to 

 watch the same orifice, at short intervals, for five hours some- 

 times observing it for a quarter of an hour at a time but still 

 the stream rolled on with a constant and equal velocity ; the cur- 

 rent then gradually diminished, and ceased in about an hour." 

 Dr. Grant, in referring to experiments made with the crumb of 

 bread sponge, (Halichondria panicea,) a common species on the 

 British coast, remarks : " Two entire round portions of this 

 Sponge were placed 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 feculent matter. 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 at a great distance ; 

 and on placing some small pieces of cork, or dry paper, over the 

 apertures, I could perceive them moving by the force of the cur- 

 rent at the distance of ten feet from the table on which the speci- 

 men rested. Naturalists have long suspected the presence of 

 very minute cilia in the gelatinous flesh of the sponge, and were 

 inclined to attribute the currents to their agency ; but as yet, 

 they had been unable to detect them by the closest scrutiny, 

 when Dr. Dobie, and afterwards Mr. Bowerbank, discovered 

 them in motion in living Sponges. It was in the sack Sponge, 

 (Crrantia compressa,} which has the form of a little flattened bag, 

 of an angular outline, of a whitish hue, with an orifice at each 

 angle, that the experienced eyes of these gentlemen detected the 

 moving cilia. " By tearing specimens in pieces, (for the use of 

 the keenest cutting instruments so crushed the texture as to de- 

 stroy the parts,) and examining the separated edges, with high 

 powers, Mr. Bowerbank found that the sides are composed of a 

 number of hexagonal cells, defined by the peculiar arrangement 

 of the triradiate spiculae, and having their walls formed by a 



