Editorial. 



That law of rhythm which pervades the inanimate world 

 seems also to preside over the incoming and outgoing of intel- 

 lectual stages and commanding personalities. Just prior to the 

 middle of this century there arose a group of geologists of pecul- 

 iar ability, and for five decades or more they have wielded 

 a most powerful influence in reshaping the doctrines of the 

 science which had been transmitted in relative immaturity from 

 the earlier fathers. For the past two decades they have taken 

 the place of these older masters as the recognized fathers of 

 geology. But we are now called upon to note that the ebb of 

 the rhythm, happily so long delayed, has of late been setting 

 sadly out. The inevitable evening tide of life that so lately 

 bore Dana away has, within the past four months, carried away 

 Daubree, Pestwich, Whitney and Green, all eminent, if not pre- 

 eminent, in their special fields. The first three had filled out 

 more than the usual span of active life, eighty-two, eighty-four 

 and seventy-six years respectively, while the last had reached 

 the ripe maturity of sixty-four years. Daubree was best known 

 for his '' Etudes SyjitJietiqiie de Geologic Experimentale ;'' Prestwich 

 for his " Geology, Che?nical, Physical ajid Stratigraphical;" Whitney 

 for his ''Metallic Wealth of tlie United States,'' and Green for his 

 " Physical Geology ; " though these are but the more conspicuous 

 among their many important treatises. Works and names like 

 these give deep inspiration to those- whose careers are yet open- 

 ing before them, and upon whom it falls to swell the incoming 

 tide that must replace, so far as it may, the outgoing one. 



*^* T. C. C. 



A UNIQUE feature of the meeting of the geological section of 

 the American Association for the Advancement of Science was 



725 



