234 RAMBLES OF A NATURALIST. 



own account, and thus contributes towards the general 

 maintenance, in the same manner as the developed 

 leaves of the young branch extract their portion of 

 nutrient elements from the atmosphere. The branch, 

 indeed, never leaves the stem from which it sprang, 

 while the Hydra, on the contrary, after having attained 

 sufficient size, separates itself from the body which 

 had previously nourished it, and begins to lead an 

 entirely independent existence. In addition to the 

 seed, properly so called, which reproduces the plant, 

 and the bud which becomes developed into a branch, 

 there exists in certain plants a kind of intermediate 

 structure, which is the bulbil. It resembles an ordi- 

 nary bud in its composition, but, like the seed, it 

 must be detached from the plant and developed apart 

 from it, before it can give origin to a new individual. 

 Animals in the same manner exhibit reproductive 

 bodies, which are at once allied to buds by their 

 structure and to ova by their functions. Let us 

 examine some of these Synhydras, a kind of polype 

 which I found on the shores of the Channel. You 

 will often observe on some old and worn shell a some- 

 what thin stratum of a fleshy substance, bristling 

 with small protuberances, and held together by a net- 

 work of horny matter. This is the polypary, or 

 common body to which the entire colony is attached, 

 The animals, which are very similar to our fresh-water 

 Hydras, have an elongated body, terminating in a 

 mouth which is surrounded by six or eight moveable 

 tentacles, which fulfil the functions of arms and hands. 

 Narrow channels, forming a network, pass from one 

 individual to the other, and maintain a communica- 

 tion between all the digestive cavities, so that the 



