DEEP-SEA FAUNA. 143 



have, as a rule, as good a support of carbonate 

 of lime in the abyss as elsewhere. 



Before proceeding to the next character, it is 

 necessary to digress a little to consider the food 

 of the animals in the abyss. In the absence of 

 any direct sun-light there can be no vegetable 

 growth, all of the animals must therefore be 

 carnivorous. The food must be either the living 

 bodies of the truly abysmal animals, or the 

 dead bodies of those that fall from the surface 

 waters. 



It is probable that the bodies of Fish and the 

 larger Invertebrates only rarely reach the bottom, 

 as they have to run the gauntlet of many dif- 

 ferent forms of life living within 100 fathoms of 

 the surface. When, therefore, such a prize does 

 fall to the luck of a deep-sea Fish, it is important 

 that it should have accommodation for it before 

 the neighbours come to share the meal. This 

 may be the cause of the fact that deep-sea Fish 

 have, as a general rule, jaws and stomach that 

 are extravagantly large, even for a carnivorous 

 creature. The width of the gape and the ex- 

 tensibility of the stomach reach their highest 

 grade in some of the deep-sea Eels, which have 

 been found containing Fish actually larger than 

 themselves. In these cases the stomach and 

 the body wall hang down from the under side 

 of the Eel's body in the form of an enormous 

 membranous sac containing the prey. 



We have now considered very briefly some of 

 the principal modifications of structure exhibited 

 by the animals of the deep-sea, but before leaving 

 the subject altogether it is necessary to refer to 



