FURTHER OBSERVATIONS ON THE ORIGIN OF THE 



GALAPAGOS ISLANDS 



ALBAN STEWART 



University of Wisconsin, Madison, Wis. 



Probably the origin of insular faunas and floras will ever re- 

 main a fascinating problem for students of geographical dis- 

 tribution. I have read with much interest ScharfFs excellent 

 book, Distribution and Origin of Life in America, 1 and with 

 especial interest that chapter that deals with the biological 

 conditions on the Galapagos Islands. I wish to offer no criti- 

 cism on this work as a whole, nor do I consider that I am in a 

 position to do so, but I do feel that an entire year of residence 

 upon these islands and my subsequent study of their flora, ex- 

 tending over a period of several years, enables me to speak with 

 some confidence about the conditions which occur there, and 

 to express an opinion concerning the origin of the flora, and of 

 the islands themselves. 



For one who is fairly well acquainted with the conditions 

 upon these islands, I do not feel that ScharfT has treated the 

 subject with entire justice. Rather it seems that he has brought 

 forward the evidence which best supports his own views in re- 

 gard to the origin of these islands, etc., and has overlooked much 

 other evidence that might well have been presented in a work 

 of so extensive a nature. 



It is hardly necessary to present in detail the different theories 

 that have been advanced to explain the origin of these islands. 

 It is sufficient to say that such authorities as Darwin, Wallace, 

 Agassiz, etc. believed that they were oceanic, and that each 

 island had arisen separately from the ocean. This theory was 

 held for many years, and Baur 2 was the first one to oppose it 



1 The MacMillan Company, N. Y., 1912. 



2 On the Origin of the Galapagos Islands. Am. Xat. xxv, pp. 217-229, 307- 

 326, 1891. 



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