AND THE LOWEE ANIMALS. 173 



From the egg of this Campanularia there springs a 

 ciliated larva, which attaches itself to a solid body, 

 becomes flattened, and then resembles a little cake, 

 which has a cavity hollowed in its substance. In the 

 centre of this, granulations make their appearance, 

 and gradually increase in size, elongate, and are con- 

 verted into a straight hollow stem, which is soon 

 covered by a transparent horny sheath. The current 

 which traverses the internal canal of the stem accu- 

 mulates the granules at the extremity of this latter, 

 and develops a true bud, which becomes organized, 

 and assumes the form of an inverted bell, closed at 

 its orifice by a horny membrane. The organized 

 material is soon detached from the inner surface of 

 this structure, and converted into a sort of conical 

 button, from which tentacles are pushed out. Finally, 

 in the centre of this mass there appears an orifice, 

 which eventually constitutes a mouth like that of 

 Hydra. The first polyp is then complete, and, bursting 

 through the membrane, it grows out like a flower 

 which has unfolded its floral envelopes. 



This primary polyp is invariably both a nurse and 

 neuter, and its office is to provide food for itself and 

 the future members of the community. These soon 

 present themselves, at first in the bud- form, but after- 

 wards, undergoing the same changes as the first, they 

 constitute an entire colony, which is by no means 

 unlike a little zigzag plant, to whose angles are 

 attached short stalks bearing these food - seeking 

 polyps. 



In the axils of the branches there now appears a 

 new series of buds. These buds are at first like the 

 former, but they are attached to a much shorter foot- 



