FISHES 129 



animal which may have been caught. The cod, as you may 

 have seen, has teeth in the roof of the mouth and in the 

 throat in addition to those found on the jaws, thus making 

 more secure its hold upon the unfortunate denizen of the 

 deep that it has seized. 



Certain fishes depend on minute forms of plants and ani- 

 mals, and therefore some means is needed by which the water 

 taken in with the food may be gotten rid of while at the same 

 time the food is retained. Hence, fishes are provided with 

 a straining apparatus which permits the water to escape 

 when the mouth is closed, and retains within the mouth the 

 minute forms of life that it has secured. Of this adapta- 

 tion for food getting, we shall learn more in our study of 

 the gills. 



Most of the fishes that prey on other animals secure their 

 victims by dint of their speed ; but one form of fish, called 



FIG. 97. Deep sea angler. 



the "deep sea angler " (Fig. 97), has upon the dorsal part of 

 the head a bulbous projection, the tip end of which is lumi- 

 nous. This bright light attracts other fishes, and when they 

 approach near enough, the " angler " makes a quick dash, 

 closes its big jaws upon the too curious individual, and so 



