268 



THE WONDER OF LIFE 



importance lies in the fact that they destroy large 

 numbers of floating fish eggs and young fry. Dr. A. G. 



Mayer writes : 



' Tender as they are 

 to the touch, passing 

 jelly-like between the 

 fingers of the hand 

 that attempts to seize 

 them, their food con- 

 sists largely of young 

 fishes, which they en- 

 gulf in great numbers, 

 seizing their prey by 

 means of their pecu- 

 liar adhesive cells. 

 Thus, in the cold 

 northern waters where 

 ctenophores occur in 

 vast swarms, they 

 constitute a serious 

 menace to the cod 

 fisheries by devouring 

 pelagic eggs and 

 young fish.' 



In almost all cases 

 the ordinary stinging 

 cells characteristic of 

 jelly-fishes and other 

 Coelenterates are ab- 



FIG. 45. Ctenophore showing (T) retractile , f n-pnnrhnro* 

 tentacles bearing adhesive cells; (M) sent irom Utenopnores, 



position of the mouth; (c) line of but their place is taken 



ciliated combs; (AS) apical spot with 



a sensory organ. (After Mayer.) by equally character- 



