SECRETS OF THE OCEAN 163 



like bunches of currants, and later will break off 

 and swim around at pleasure in the water. Occa- 

 sionally one is fortunate enough to discover these 

 . small jellies in a pool where they can be photo- 

 graphed as they pulsate back and forth. When 

 these attain their full size they lay eggs which 

 sink to the bottom and grow up into the plant-like 

 hydroids. So each generation of these interesting 

 creatures is entirely unlike that which immedi- 

 ately precedes or follows it. In other yrords, a 

 hydroid is exactly like its grandmother and grand- 

 daughter, but as different from its parents and 

 children in appearance as a plant is from an ani- 

 mal. Even in a fairy-story book this would be 

 wonderful, but here it is taking place under our 

 very eyes, as are scores of other transformations 

 and "miracles in miniature" in this marvellous 

 jmderworld. 



Now let us deliberately pass by all the attrac- 

 tions of the middle zone of tide-pools and on as 

 far as the lowest level of the water ;will admit. 

 .We are far out from the shore and mapy feet 

 below the level of the barnacle-covered boulders 

 over which we first clambered. Now we may 

 indeed be prepared for strange sights, for we are 

 on the very border-land of the vast unknown. The 

 abyss in front of us is like planetary space, un- 

 known to the feet of man. While we know the lat- 

 ter by scant glimpses through our telescopes, the 

 former has only been scratched by the hauls of 



