332 ORIGIN OF LIFE IN AMERICA 



trend the isthmus of Panama runs in an east-westward direc- 

 tion. 



That this Pacific land persisted to some extent until com- 

 paratively recent geological times, seems to be indicated by 

 several notable features. When Mr. Agassiz surveyed the 

 ocean floor from the steamer " Albatross," he found the Pacific 

 side of Panama faunistically poor compared with the Atlantic 

 side, but he attributed that condition to the absence of a great 

 oceanic current on the south side of the isthmus. The absence 

 of deep-sea corals on the Pacific side was most striking. Yet, 

 he remarks that there is on the west coast of Central America, 

 even in deep water, a considerable fauna, which finds its 

 parallel in the West Indies and recalls later Cretaceous times 

 when the Caribbean Sea was practically a bay of the Pacific. 

 This assumption that the Caribbean Sea was once a bay of 

 the Pacific has been put forward by other writers. The 

 faunistic resemblance, or parallelism, as we might call it, 

 between the seas on each side of Central America may be due 

 to a former westward extension of the Atlantic Ocean just 

 as much as to an eastward extension of the Pacific. However, 

 one of the most remarkable features brought to light by the 

 " Albatross " expedition was the condition of the ocean 

 floor. There was not a station between Acapulco, on the 

 coast of Mexico, and the Galapagos islands, according to 

 Mr. Agassiz, of which the bottom could be characterised as 

 istrictly oceanic. At the most distant points from the 

 shore the bottom specimens invariably showed some trace of 

 admixture of terrigenous material. All the way, even to a 

 depth of 2,000 fathoms, the trawl became filled with a sticky 

 mud containing logs of wood, branches, twigs and decayed 

 vegetable matter. Being a firm believer in the permanence 

 of ocean basins, Mr. Agassiz * naturally attributed this extra- 

 ordinary condition of the sea floor to the existence of currents, 

 which, striking Central America from north and south, are 

 reflected in a westward direction. He likewise argues from 

 this discovery that it offers a very practical object lesson re- 

 garding the manner in which the Galapagos islands received 

 their fauna and flora. The peculiar condition of the ocean 



* Agassiz, A., "Eeportson 'Albatross': Expedition," pp. 11—77. 



