Vol. 4] 



Holway.—Cold Water Belt. 



285 



time for the development of a slow but constant deep water 

 movement in the direction of the prevailing wind. The north- 

 eastern part of the North Pacific is pre-eminently the place for 

 the development of a uniform drift from surface to bottom, as 

 may be seen by' studying the contours in PL 36. The contours 

 show a remarkable great ocean basin uninterrupted by islands 

 and bounded on the north and east by a regular but steep con- 

 tinental slope. This regularity of basin of the North Pacific is 

 more noticeable if for comparison we examine a bathymetrical 

 chart of the North Atlantic. In the latter we have the mid- 

 Atlantic ridge running in a general north and south direction 

 and making two great subdivisions of the basin. We have also 

 the wide openings on the west and on the east of Greenland and 

 connecting with the cold water of the Arctic Ocean. In the 

 Pacific there is but one great opening into Bering Sea and that 

 sea is connected with the Arctic by Bering Strait, which is both 

 narrow and shallow. Considering then its practical lack of 

 connection with the Arctic Ocean and its uninterrupted basin 

 and relatively regular shores, it is a reasonable supposition that 

 the northern half of the North Pacific has a more regular system 

 of oceanic circulation than has the North Atlantic. 



SUMMARV. 



Several interesting points for future investigation are sug- 

 gested by the observations and theories discussed in this paper. 

 From the biological standpoint it will be interesting to find 

 whether the cold water and the variations in temperature near 

 Cape Blanco are a barrier to species that might normally ex- 

 pand into the regions lying to the northward. The investiga- 

 tion of the area lying to the southwest of the coast from Point 

 Conception to San Diego, now being carried on under the direc- 

 tion of Professor William E. Bitter of the University of Cali- 

 fornia, should in the next few years give us more accurate in- 

 formation concerning the disputed temperature relations of this 

 portion of the Pacific as well as a better knowledge of the marine 

 life of the region and the temperature limitations of this life. 



