5o6 IJFE IN THE DEEP SEA. 



ing, not only as showing that deep-sea animals must derive 

 food largely from such sources, but because they are necessarily 

 of great geological importance as showing how specimens of 

 land vegetation are becoming imbedded in deposits which 

 are being formed at very great depths. 



Between the Fiji Group and the New Hebrides we dredged 

 from 1,450 fathoms a piece of a branch of a tree, 3 feet in 

 length. Off the Island of Palma, one of the Azores, we 

 dredged from 1,135 fathoms the leaf of a Shrub, possibly a 

 Holly-leaf, which was still green and firm, though water-logged. 

 With this leaf were numerous fish otoliths and eye-lenses. We 

 constantly dredged bones of whales and fish from great depths. 

 Off the coast of Nova Scotia we dredged a quantity of glacially 

 striated stones. 



The deep-sea animals of course prey upon one another just 

 as do shallow-water species. We dredged once a fish from 2,500 

 fathoms which had a deep-sea Shrimp in its stomach. A 

 Ceriaiithiis dredged from 2,175 fathoms had a small Crustacean 

 in its stomach. 



The waters of the deep sea being everywhere dark and 

 always cold, the conditions of life in them are the same all 

 over the world. The temperature of the deep sea is practically 

 the same, as far as effect on life is concerned, under the 

 Equator and at the Poles. Hence there are absolutely no 

 barriers to the migrations of animals in the deep sea. Time 

 only is required for any deep-sea animal to roam from any 

 distant part of the earth to another. 



It is only in the strata of water comparatively near the 

 ocean surface that there is any great difference in range of 

 temperature in various latitudes. Up to the depth of 1,000 

 fathoms, even from the greatest existing depths, the range 

 amounts only to a few degrees Fahrenheit ; and at 1,000 

 fathoms everywhere the water is cold and dark, and the con- 

 ditions of life practically the same as those in the greatest 

 depths ; even at a depth of 500 fathoms the water is almost 

 everywhere as cold as 40° F. The effects of difference of 

 pressure may be neglected, since, when encountered gradually, 

 they would be of no injury to migrating animals. 



Hence, even the ridges, which project up from the ocean 

 floor and separate areas of great depth from one another by 

 intervening expanses, over which the depth is only 1,000 

 fathoms or somewhat less, do not oppose any obstacle to the 

 migration of deep-sea animals. Such ridges exist in the 

 Atlantic and Pacific Oceans. 



In the Atlantic, a long sinuous ridge, with a depth of only 

 1,000 fathoms over it, separates the two deep troughs on 



