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to raise its level all along the coasts, facilitating its appearance 

 at the surface as off northwest Africa, southern California 

 and the Kuril Islands. 



It is on account of the fact that the abyssal circulation of 

 the oceans is anticlockwise about their entire periphery, and 

 that therefore in the southern and eastern portions of their 

 basins these currents lose in the southern hemisphere a vast 

 amount of water from their inner (northern or western) border, 

 while in the northern hemisphere they are by the same force 

 drawn away from the abysses and pressed against the coasts, 

 that large, deep and powerful currents, carrying an enormous 

 volume of water, such as the Kuro-Siwo in the Pacific and the 

 Gulf Stream in the Atlantic, can exist only in the northern 

 hemisphere ; for in the southern hemisphere the bottom water 

 is maintained at such a high level that the existence of large 

 and powerful currents above it is not possible. 



Therefore the abysses of the southern hemisphere would be 

 better fitted to support abyssal life than those of the northern 

 hemisphere, and so far as our limited knowledge of the facts 

 permits us to judge, abyssal life is actually more abundant in 

 the south. 



Both in the Atlantic and in the Pacific north of the equator 

 the littoral crinoids living within the influence of the antarctic 

 water descend to very considerable depths on the eastern 

 and northern shores, but on the western shore the littoral 

 crinoids, which live within the influence of currents superposed 

 upon the antarctic water, possess only a very small bathymétrie 

 range. This is due to the fact that the physical conditions in 

 the east and north are such that the only barrier to unlimited 

 descent is the question of food supply, while on the western 

 coast there are also physical barriers of temperature to be 

 considered. 



Similarly south of the equator in the Pacific, Atlantic and 

 Indian Oceans the truly abyssal crinoids approach nearer the 

 surface on the western than on the eastern shores. The infer- 

 ence is that truly abyssal conditions, biologically speaking, 

 occur nearer the surface in the west than they do in the east. 



