JELLY-FISHES. 323 



surface of this creeping root, a kind of wart buds forth, 

 and soon grows into an erect slender stem, which 

 presently divides into four straight, taper, slightly 

 divergent tentacles, which grow straight upward to a 

 considerable length. The whole structure retains the 

 rich purple hue of the original gemmule. 



Beyond this point I have not pursued the history of 

 the little Turris from personal observation; nor am I 

 aware that any naturalist besides has studied the de- 

 velopment of this particular genus. But the history of 

 other genera is known; and as the phenomena they 

 exhibit are quite parallel to those which I have been 

 describing, so far as these have been traced, we may 

 fairly conclude that there is the same parallelism in the 

 subsequent stages. 



Assuming this, then, the little crimson stem with four 

 rays, — a veritable polype, — buds four more tentacles in 

 the interspaces, making the total number eight; these in 

 like manner increase progressively to sixteen, thirty-two, 

 and sixty-four. It now possesses a close resemblance to 

 the Hydra of our ditches, only having more tentacles; 

 &nd, like it, the Medusa-larva buds forth from its sides 

 young Hydra-like polypes, which take the form of their 

 immediate parent, fall off, attach themselves, bud forth 

 more, and so on. All these catch living prey with their 

 tentacles, swallow them with their mouths, and digest 

 them with their stomachs, exactly like real polypes, and 

 thus produce generation after generation of similar 

 beings. 



Years may pass in this stage, during which number- 

 less polypes are formed. At length the original stock, 

 or any one of its descendants, takes-on an important 

 change. Its body lengthens, and becomes cut as it were 

 into a number of rings, as if tied tightly round with 

 thread, or like the body of an Annelid. These segments 

 become increasingly distinct, until at length each is seen 



y 2 



