SCIENCE 



A WEEKLY JOURNAL DEVOTED TO THE ADVANCEMENT OF SCIENCE, PUBLISHING THE 



OFFICIAL NOTICES AND PROCEEDINGS OF THE AMERICAN ASSOCIATION 



FOR THE ADVANCEMENT OF SCIENCE. 



Friday, November 3, 1905. 



COISITEH^TS. 



The Origin of Species through Isolation: 

 Peesident David Stake Jokdan 5 5 



Scientific Books:— 



Canard's Tlie Waterlilies : Pkofessoe 

 Chakles E. Bessey. Fellogg's American 

 Insects: C. L. Maklatt. Bagley on the 

 Educative Process: Peofessoe Wilbxje S. 

 Jackma^s^. Freund on the Study of 

 Chemical Composition: Peofessoe Louis 

 Kahlenbeeg 562 



Scientific Journals and Articles f67 



Discussion and Correspondence: — 



Cyanide of Potassium: De. F. J. H. Mee- 



ETLL 568 



Special Articles: — 



The Parachute Effect of Thistle-down: J. 

 B. Dandeno. The Weight of the Bronto- 

 saurus : W. K. Gbegoey [68 



Quotations : — 



College Administration 572 



The Bird Life of Central Illinois 573 



TJie International Congress of Americanists. 674 



Scientific Notes and News 574 



University and Educational News 576 



MSS. intended for pabiicatiou aud books, etc., Intended 

 for review shouid be sent to tbe Editor of Science, •■iH.rr- 

 BOu-on-HHdsou, N. Y. 



THE ORIGIN OF SPECIES THROUGH 

 ISOLATION. 



For me, it is the chorology of organisms, that 

 is to say, the study of all the important phe- 

 nomena embraced in the geography of animals and 

 plants, which is the surest guide to the study of 

 the real phases in the process of the formation of 

 species. (Moritz Wagner.) 



It is now nearly forty years since Moritz 

 Wagner (1868) first made it clear that 

 geographical isolation (raumliche Sonder- 

 ung) was a factor or condition in the for- 

 mation of every species, race or tribe of 

 animal or plant we know on the face of 

 the earth. This conclusion is accepted as 

 almost self-evident by every competent 

 student of species or of the geographical 

 distribution of species. But to those who 

 approach the subject of evolution from 

 some other side the principles set forth by 

 Wagner seem less clear. They have never 

 been confuted, scarcely even attacked, so 

 far as the present writer remembers, but 

 in the literature of evolution of the present 

 day they have been almost universally 

 ignored. Nowadays much of our discus- 

 sion turns on the question of whether or 

 not minute favorable variations would en- 

 able their possessors little by little to gain 

 on the parent stock, so that a new species 

 would be established side by side with the 

 old, or on whether a wide fluctuation or 

 mutation would give rise to a new species 

 which would hold its own in competition 

 with its parent. In theory, either of these 

 conditions might exist. In fact, both of 

 them are virtually unknown. In nature a 

 closely related distinct species is not often 



