THE PHYSIOLOGY OF DEEP-SEA LIFE. 299 



The specific gravity of the surface water of the American 

 coast, as worked up by Mr. Buchanan from the observations of 

 the ," Challenger " and other vessels, is as follows : — 



In the Atlantic outside of the West India Islands (Fig. 194), 

 close to the American coast, on a line about at the end of the 



Fig. 194. — Specific Gravity of Sea-Water. Western N. Atlantic. (Buchanan.) 



Bahamas, it varies between 1.0270 and 1.0275. In the Carib- 

 bean and Gulf of Mexico, as well as waters parallel to the 

 Atlantic coast as far as Cape Hatteras, and after that along the 

 course of the hundred-fathom line, it is between 1.0265 and 

 1.0270. For the waters within a line drawn from Newfound- 

 land to Cape Cod, the specific gravity is below 1.0260. 



The saltest water was found by the " Challenger " in the middle 



