EASTERN PACIFIC EXPEDITION 435 



tigations was the amount of variation from type that 

 may be expected in a given period of geological time, as 

 illustrated by the difference in the fauna on the two 

 sides of the Isthmus of Panama since the days when 

 the Caribbean was virtually a bay of the Pacific. The 

 reports of the specialists on his material collected on 

 both sides of the Isthmus were to be made with this end 

 in view ; while the preliminary geological studies, carried 

 on in connection with his study of West Indian coral 

 reefs, had been extended under his direction by Hill 

 and others, so that he felt that he had an approximate 

 idea of the period. 



When he was chosen president of the International 

 Zoological Congress of 1907, he first selected this ques- 

 tion as the subject of his presidential address. But feel- 

 ing that he had not yet received the reports of a suffi- 

 cient number of his collaborators to make as complete a 

 study of the subject as he desired, he finally abandoned 

 it in favor of a summary of American oceanography. 



It is one of the tragedies of a full life that so much 

 must be left unfinished. His " Panamic Report," so long 

 looked forward to, was never written. Thus the great- 

 est quantitative study of the progress of evolution ever 

 attempted was left without the final touch of the master 

 hand. 



The following winter of 1905-06 he spent on the 

 Nile, where he had passed a winter just twenty years 

 before. At Luxor he was much interested in visiting, 

 in the Valley of the Kings, the excavations of his New- 

 port neighbor, Mr. Theodore Davis. The archaeological 

 treasures which that gentleman has unearthed are now 

 well known to every one who has heard anything of 

 Egypt, and it may be worth noting that his first interest 



