250 



FIRST YEAR SCIENCE 



Fig. 110. 



and coral polyp, are fixed, and rely upon the currents of 

 the water to bring them their food, while others, like the 

 crab, the lobster and the fish, move from place 

 to place in search of prey. 



In the warmer seas the surface water is often 

 filled with minute microscopical animals which 

 have the power, when disturbed, of emitting 

 light, so that when a boat glides through these 

 waters, a trail of sparkling silver seems to fol- 

 low in the wake. 



Between the surface and the bottom of the 

 deep ocean there seems to be a vast depth of 

 water almost devoid of life. This region, like the bot- 

 tom of the ocean, has been little explored and there may 

 be life here which has not been discovered. From the 

 bottom of the sea the dredge has brought up some very 

 curious forms of life. Here under tremendous pressure 

 and in profound darkness have been developed species of 

 carnivorous fishes. 



Some of these have 

 large peculiarly well- 

 developed eyes and 

 others have not even 

 the rudiments of eyes. 

 As the light of the sun 

 never penetrates to these 

 depths, it would seem 

 at first that eyes could 

 be of no use to animals, 

 but it has been found 

 that some of the ani- 

 mals of the ocean bottom have the power of emitting 

 light in some such way as the glowworm and firefly do, 

 and it is probable that it is to see this phosphorescent 



FLYING FISH. 



Notice how the front fins have become 

 wing-like. 



