ANATOMY. . 293 



been that period in the planet's history and not so 

 dreary either to contemplate in comparison with that 

 of the Devonian and Carboniferous periods, when the 

 smaller fishes were the legitimate prey of the larger 

 when the largest sharks consumed a school of fishes a 

 day. Those were horrible feasts, and so are those 

 held by smaller fishes to-day. The ten -pound pike 

 has had a two-pound trout taken from its maw. 

 "Game fish,' ? so called, must have living food, and 

 the appetite of such is almost insatiable. Survey their 

 mouths, and be amazed at the dental display. Long 

 and slender teeth are set so that no victim can escape 

 the way in is in one direction, and that is through 

 barbed fauces, " nulla vestigia retrorsum" 



The shape of a handsome fish is admirable for 

 swimming; the fins are perfect poisers and propellers; 

 its tail is un equaled as an instrument of propulsion ; 

 its iridescent scales, laid on in artistic rows, constitute 

 beautiful shields against injury, and an envelope to 

 lessen friction in gliding through the water. The 

 gills, with mobile covers, are charmingly adapted to 

 aeration effected in a watery environment. The mus- 

 cular force of fishes is immense; the ribs are exceed- 

 ingly tough, and there is a layer of elastic cartilage 

 between the vertebrae. 



In a cursory consideration of comparative anat- 

 omy, the shell fishes mollusca must not be left un- 

 mentioned. The calcareous cover of the humble snail 

 in the garden walk is highly ornamental in form ami 

 tints; and being a part of the creature, it is borne 

 about with ease. The mollusk may be considered "at 

 home" wheresoever it goes, but its latch string is not 

 always out. Two shelled niollusks oysters and clams 

 are famous for foods the world over. The muscular 



