February 23, 1906.] 



SCIENCE. 



307 



and are regarded as outwash deposits incident 

 to the earlier glaciation. Between these 

 highest gravels and the valley train of the last 

 stage of glaciation several intermediate gravel- 

 covered terraces occur that are believed to 

 have been developed during the period of in- 

 terglacial erosion vehich accomplished the dis- 

 section of the old surfaces upon which the 

 early drift was deposited. 



Arthur C. Spencer, 

 Secretary. 



THE TORREY BOTANICAL CLUB. 



A MEETING of the club was held on January 

 9, at the American Museum of Natural His- 

 tory, with President Eusby in the chair. Six- 

 teen persons were present. 



The annual reports of the treasurer, secre- 

 tary, corresponding secretary, editor and the 

 editor of Torreya were then read and placed 

 on file. The committee on phanerogams, and 

 the committee on cryptogams reported prog- 

 ress. 



The following officers were elected for the 

 ensuing year : 



President — Dr. H. H. Rusby. 



Vice-Presidents — Dr. Edward S. Burgess, Pro- 

 fessor L. M. Underwood. 



Recording Secretary — Dr. C. Stuart Gager. 



Corresponding Secretary — Dr. John K. Small. 



Editor — Dr. John Hendley Barnhart. 



Treasurer — Dr. Carlton C. Curtis. 



Associate Editors — Dr. Alex. W. Evans, Dr. 

 Tracey E. Hazen, Dr. Marshall A. Howe, Dr. D. 

 T. MaeDougal, Dr. W. A. Murrill, Dr. Herbert M. 

 Richards, Anna Murray Vail. 



A request from Mrs. E. G. Britton for a 

 grant of $100 from the Herrman fund to be 

 used in illustrating new species of mosses 

 from the southern states and the West Indies 

 was read and the application approved by the 

 club. 



C. Stuart Gager, 



Secretary. 



THE ELISHA MITCHELL SCIENTIFIC SOCIETY OF THE 

 UNIVERSITY OF NORTH CAROLINA. 



The 162d meeting was held in the chemical 

 lecture room, on Tuesday, January 23, 7:30 

 P.M. Under the topic ' Tropical Notes,' Pro- 



fessor W. C. Coker described in a most inter- 

 esting way a recent botanical trip to southern 

 Florida and Cuba. Numerous specimens of 

 plants were exhibited. The program was con- 

 cluded by Professor Archibald Henderson, 

 who discussed ' A Group of Cross Ratios.' 

 A. S. Wheeler, 

 Recording Secretary. 



DISCUSSION AND CORRESPONDENCE. 



ECOLOGICAL ADAPTATION AND ECOLOGICAL 



SELECTION. 



It seems that in the recent discussion of 

 evolution there is too much importance at- 

 tached to variation. It is not so certain that 

 variation itself, or the elucidation of the ques- 

 tion how certain species came to have certain 

 characters, is the most important question in 

 the origin of species. The segregation of 

 species may be only an ecological process in 

 which the matter of structural variation is of 

 secondary importance. In fact the Darwinian 

 theory does not require the supposition that 

 the origin of a new species begins with a 

 change of structure, so that to insist upon the 

 importance of ecological selection is only to 

 emphasize a factor already recognized by Dar- 

 win. By limiting the development of species 

 to the assumption of structural characters the 

 theory of natural selection is made to appear 

 at an unfair disadvantage. Species are char- 

 acterized by non-competitive habits rather 

 than by adaptive structures. Indeed, I hold 

 that the origin of a new species begins with a 

 change of place or habits and that the char- 

 acters by which species are distinguished, as 

 well as adaptive structures, follow as a conse- 

 quence. 



In the ' Origin of Species ' there are several 

 passages in which a change of habits is speci- 

 fied as a condition of selection. " For as all 

 of the inhabitants of each country are strug- 

 gling together with nicely balanced forces, 

 extremely slight modifications in the structure 

 or habits of one species would often give it an 

 advantage over others" (p. 64). "The more 

 diversified the descendants from any one spe- 

 cies become in structure, constitution and 

 habits, by so much the more will they be en- 



