The Fresh-Water Polijpi. 605 



the same water ; and feed on the various species of small 

 worms and other aquatic animals within their reach. 

 When any of these pass near a Polyp, the latter sud- 

 denly catches it with its arms, and dragging it to its 

 mouth, swallows it by degrees, much in the same man- 

 ner as a snake gorges its prey. Two Polypi may 

 occasionally be seen in the act of seizing the same worm 

 at different ends, and dragging it in opposite directions 

 with great force. It sometimes happens, that while one 

 is swallowing the end it has seized, the other is employed 

 in the same manner ; and thus they continue swallow- 

 ing, each his part, until their mouths meet. They then 

 rest for some time in this situation, till the worm breaks 

 between them, and each goes off with his share. But 

 sometimes when the mouths of both are thus joined 

 together a combat ensues, and the largest Polyp usually 

 swallows his antagonist; the animal thus swallowed, 

 however, seems to be a gainer by its misfortune, as after 

 it has lain in the conqueror's body for about an hour it 

 issues unhurt, and often in possession of the prey that 

 had been the original cause of contention. The remains 

 of the animal, on which the Polyp feeds, are evacuated 

 at the mouth, the only opening in the body. The species 

 are multiplied by a kind of vegetation, one or two, or 

 even more young ones, emerging gradually from the sides 

 of the parent animal; and these young ones are fre- 

 quently again prolific before they drop off; so that it is 

 no uncommon thing to see two or three generations at 

 once on the same Polyp. But the most astonishing fact 

 respecting this animal is, that if a Polyp be cut in 

 pieces, it is not destroyed, but is multiplied by dissection. 

 It may be cut in every direction that fancy can suggest, 

 and even into very minute divisions, and not only the 

 parent stock will remain uninjured, but every section 

 will become an animal. Even when turned inside out, 

 it suffers no material injury ; for, in that state it will 

 soon begin to take food, and to perform all its other 

 natural functions. 



M. Trembley, of Geneva, ascertained that different 

 portions of one Polyp could be engrafted on another. 

 Two transverse sections brousrht into contact will quickly 



