468 ANNUAL EEPORT SMITHSONIAN INSTTTUTION, 1910. 



when struck with a hammer. One sometimes finds shells of the giant 

 clam, Tridacna^ imbedded in this hard limestone and elevated above 

 the sea, and jQt the nacre of the shell is still white and polished, thus 

 proving that the rock was elevated only recently, and certainly not 

 longer ago than in late Tertiary times. 



Altogether the most interesting problem raised by Alexander 

 Agassiz's researches in the Pacific is the question of the relation be- 

 tween these elevated Tertiary reefs and the growing coral reefs of to- 

 day, and it still remains unsolved, despite the careful studies made by 

 Mr. E. C. Andrews, whom Alexander Agassiz sent to the Fiji Islands 

 especially to study this problem, for Andrews's investigation has 

 merely served to show that the subject is very complex and can not 

 be solved until prolonged study of certain favorable localities has 

 been completed. 



From August, 1899, until March, 1900, Alexander Agassiz had for 

 the second time the scientific direction of the Albatross. Commander 

 Jefferson F. Moser, United States Navy, was in command and the 

 cruise began at San Francisco and extended across the tropical re- 

 gions of the Pacific to the Ladrone Islands and thence northward to 

 Japan. On this great cruise the Albatross visited the Marquesas, 

 Paumotos, Society, Cook, Nieue, Tonga, Fiji, Ellice, Gilbert, Mar- 

 shall, Caroline, and Ladrone Islands, steaming many thousands of 

 miles in and out among the atolls. 



From San Francisco the vessel steamed 4,000 miles straight to the 

 Marquesas, making many soundings and trawl hauls which led to the 

 discovery that there is here a great basin between 2,500 and 3,000 

 fathoms deep, the bottom of which is covered with manganese nodules 

 and the teeth of extinct sharks. It was an impressive sight to see the 

 great trawl bring up tons of the manganese nodules looking like 

 gritty brown potatoes, and all nearly as cold as ice, for the tempera- 

 ture of the deep floor of the ocean here was less than 3° F. above freez- 

 ing. Despite the heat of the tropic sun beating upon our deck our 

 hands stung with the cold as we felt among the mass of nodules and 

 cracked them open to discover the inclosed nucleus of pumice, the 

 encrusted ear bone of an extinct whale or a shark's tooth imbedded 

 in the soft brown rock. Some of these shark's teeth were so large 

 that the shark itself was probably more than 100 feet long. A deep 

 submarine area far greater than that of the United States is covered 

 thickly by these manganese nodules and sharks' teeth, and Alexander 

 Agassiz named it the " Moser Deep," in honor of the commander of 

 the Albatross. 



Very little animal life was found, either floating in the sea or on the 

 bottom, over this vast desert of manganese nodules. 



The chief result of this expedition was the discovery that a wide- 

 spread elevation of the Pacific islands occurred in late Tertiary times. 



