SCIENCE 



Friday, June 18, 1920 



CONTENTS 



The Survival of the Unlike: Professor Wil- 

 liam Trelease 599 



Tlie Structure of the Helium Atom: Dr. Ir- 

 ving Langmuir 605 



Alfred Werner 607 



Scientific Events: — 



Tlie United States Coast an^ Geodetic Sur- 

 vey and Becent Congressional Legislation; 

 The BocTcefeller Foundation's Bndowment- 

 of University College, London; Gifts to Uni- 

 versities and Colleges; Endowment of the 

 Medical School of the University of 

 Eochester 608 



Smentifio Notes and News 611 



and Educational News 613 



Discussion and Correspondence: — 



Scientific Work in the Hawaiian Islands: 

 Dr. HEisfRY FAmriELD Osborn. The Energy 

 of Small Oscillations : Dr. Warken Weaver. 

 Carbon Dioxide and Increased Crop Produc- 

 tion: M. W. Senstitjs. Vacancies in the 

 Grade of Assistant Civil Engineer, U. S. 

 Navy: C. W. Parks 613 



Aristotle and Galileo on Falling Bodies: Pro- 

 fessor Florian Cajori 615 



Special Articles: — 

 An Accurately Controllable Micropipette : 

 De. 0. V. Taylor 617 



The American Philosophical Society: Peo- 



FESSOE ARTHUR W. GOODSPEED 61 8 



MSS. intended for 'publication and books, etc., intended for 

 review skonld be Bent to The Editor of Science, Garrison-on- 

 Hudson, N. Y. 



THE SURVIVAL OF THE UNLIKEi 



Some years ago, studying ' the agaves or 

 century plants of the West Indies, I found 

 that they represent not only many species but 

 numerous rather distinct groups, and that the- 

 aggregates of individuals that we call species, 

 and of species in these larger groups, resemble 

 and differ from one another in a sort of pro- 

 portion to the depth of water between the 

 islands on which they are found, which was 

 translated into differences somewhat propor- 

 tionate to the length of time that their 

 habitats have been separated by water bar- 

 riers. 



Those of near-by and apparently rather 

 recently separated islands were not found to 

 differ progressively and adaptatively in a 

 single character such as flower-shape or size 

 of seed-vessels nor was there a correlated 

 difference in these respects, but sometimes one 

 and sometimes another such character was 

 different, while no indication was evident that 

 the plants were not living under essentially 

 identical conditions so far as pollination and 

 dissemination are concerned. 



When the idea of organic evolution was 

 presented before the Linnean Society in 1858 

 in a convincing way, by Darwin and Wallace, 

 the latter spoke of the process as a survival of 

 the fittest, and the former, as the result of 

 natural selection, in the struggle for existence 

 which effects kinds or species as well as 

 individuals of living things. 



The dissociation of parts of the ancestral 

 stock of these West Indian agaves without 

 any marked climatic difference in their homes 

 appeared to me to have left each final island 

 with a stock essentially in harmony with its 

 environment and capable of deviating con- 

 siderably in flower and fruit proportions from 



1 Address of the president before the lUinois 

 Chapter of the Society of the Sigma Xi, May 19, 

 1920. 



