LIFE, IN ITS LOWER FORMS, 



the economy of these animals which appealed so anoma- 

 lous, was the mode in which they were both naturally 

 and artificially multiplied. They were manifestly animals, 

 yet it was found that they could be propagated by slips 

 or cuttings, like plants ! In the warm weather of sum- 

 mer each polype is observed to shoot forth, from various 

 parts of its body, little warts, or knobs, which increase 

 rapidly, until in a few days they assume the form of the 

 parent animal, each one being furnished with a circle of 

 tentacles, though still attached at its lower end. The 

 young one, which up to this period had received its nutri- 

 ment from the parent's stomach, from which a channel 

 had communicated with its own, now catches prey with 

 its own tentacles, the duct closes, the connexion of the 

 base with the mother becomes more slender, and at xongtn 

 the little animal falls off, and commences independent 

 life. Such is the ordinary mode of increase — generation 

 by gemmation. 



In autumn, the Hydra propagates by means of eggs, 

 which are deposited around the parent ; the basal portion 

 of her body being spread over them, and becoming a horny 

 protecting skin. She immediately dies, and the eggs are 

 hatched in the ensuing spring.* 



But these strange animals may be artificially increased 

 at pleasure, and that by means which, to higher animals, 

 would inevitably destroy, instead of multiplying life. If 

 the head of a polype, with all its tentacles, be cut off from 

 the trunk with scissors, it will presently develop a new 

 trunk and base, while the headless trunk begins to shoot 

 out new tentacles ; and thus, in a little time, two perfect 



* Laurent, L' Institute No. 465. 



