128 THE MICK08COPIST IN BERMUDA. 



of generation ; and it is for that reason that I bring them for- 

 ward. Certain buds of this plant-like organism, instead of 

 growing as usual into feeding members of the colony, become 

 cells or capsules in which are formed and sent out one after 

 another little animals bearing not the slightest resemblance to 

 the hydroid polyps. In fact they are jelly fishes, medusae, those 

 inert umbrella-shaped masses of jelly which we have all seen 

 lazily floating about in the sea, or lying stranded on the shore. 

 Of course there has been a rapid and perfectly enormous growth 

 between the microscopic forms first produced and the jelly fishes 

 as we have seen them. After attaining this growth and maturity, 

 the medusee produce what are called ciliated gemmules, which are 

 simply hatched eggs provided with vibratile cilia. By means 

 of these swimming hairs the embryos move about in the water, 

 but finally settle to the bottom, become attached to some shell or 

 rock, and grow into perfect Hydra with tentacles and horny 

 cups, from which other polyps bud off until we have again the 

 plant-like tuft from which we started. 



All the numerous individuals of a hydroid colony are connected 

 to a common alimentary canal running through the center of all 

 the branches. There is therefore but one animal, though having 

 many heads, like the fabled Hydra from which its name is 

 derived. Constructed on one of the simplest plans of nature, 

 with only its feeding arms, and a stomach common to the whole 

 community, fixed for life to its permanent base, this creature, 

 apparently so un cared for, at the proper season, like the tree 

 which it simulates, pushes out a profusion of flower buds, from 

 which it detaches the flowrets one after another and sends them 

 forth to bear seed and to. disseminate far and wide its progeny. 

 All its needs are thus wonderfully provided for. But it is at the 

 cost of operating almost a biological miracle. For an animal of 

 one form and habit and life has begotten another of totally dif- 

 ferent form and habit and life ; and this one after swelling to 

 enormous proportions and voyaging the ocean for a time like a 

 water baloon, has finally produced not its like, nor anything 

 resembling itself but a brood of little insignificant polyps, that 

 take root and vegetate like the lowest things that live. 



