7 , ; NATURAL HISTORY 



their beauty. It is interesting to note that, like the fresh-water sponges 

 xibed on a preceding page, they form < winter eggs' or 4 statoblasts/ 

 to enable them to pass the winter months. These are not true eggs, but 

 are to be regarded rather as modified buds. Each is enveloped in a hard- 

 ened case, usually flattened, and resembling two watch-glasses placed 

 together, and bearing around the edge a series of anchor-like hooks, the 

 purpose of which is to prevent the whole from being washed away by the 

 freshets of spring. 



