22 EHIZOPODA. 



opaque masses, which it strewed everywhere 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 withdi-aw my eye from fatigue, without 

 having seen the torrent for one instant change its 

 dhection, 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 sponges perpetuate their race by a very 

 curious mode of increase. At stated periods there 

 project from the interior of the larger canals, that 

 traverse their substance in all dhections, minute oval 

 masses of jelly, which grow, till at length they are 

 detached and driven out by the issuing currents into 

 the surrounding water. One would naturally expect 

 that such apparently helpless atoms would fall at 

 once to the bottom ; but in such a case how^ could 

 the species be dispersed? Here we behold with 

 wonder a beautiful instance of providential care. A 

 power of locomotion is conferred upon the offspring, 

 which is not possessed by the parent sponge ; for, 

 whereas the latter is firmly rooted to the bottom, 

 incapable of changing its place, the little germ is 

 able to swim rapidly through the sea. This is 

 effected by cilia, or minute hairs, with which one 

 end of the pear-shaped gemmule is beset ; tliese con- 

 stantly keep up a rapid vibration, and thus row the 

 embryo sponge from place to place, until it reaches a 

 distant and suitable spot, where it quietly settles 

 down, and soon takes the form peculiar to its species. 



Were we to inform our young readers that flints 

 have been sponges, and that every flint wherewith, in 

 many parts of the country, the roads are paved, and 

 which, before the invention of lucifer matches, con- 

 stituted almost the only means of obtaining fire, had 

 grown at the bottom of the sea, rooted upon rocks, 



