ORIGIN OF THE GALAPAGOS ISLANDS 193 



seriously. His theory was, that the islands had all been joined 

 together at some time in the past, and at a still earlier period 

 they had been connected with the continent of North America, 

 presumably in the region of Central America. Baur had not 

 been upon the islands when he formulated his theory, but he 

 visited them subsequently, apparently in part to obtain evi- 

 dence to support his views. My own study of the flora of these 

 islands 3 led me to a somewhat different view from either of the 

 above — viz., that they are truly oceanic in their origin, but that 

 they have been connected together at some time in the past 

 in such a way as to form one or more larger islands, which by 

 subsidence has resulted in the present condition. From the 

 study of the flora I found no evidence which would lead me to 

 believe that a land connection with either of the American con- 

 tinents had ever existed. In fact most of the evidence would 

 lead to the opposite conclusion. As these views have been set 

 forth in a former paper, 4 it is unnecessary to repeat them here. 



I do not wish to go into the zoological side of the question 

 to any extent as there are others who are better qualified to 

 criticise this part of the work than myself. I will, however, dwell 

 briefly on a few important matters. It would have been rather 

 appropriate for Scharff to have offered some explanation as to 

 why there is a fairly abundant reptilian fauna upon the islands 

 and at the same time an entire absence of batrachians. It 

 would also have been well for him to have explained why the 

 mammalian fauna, other than that which is known to have been 

 introduced by man, consists only of bats, mice, and rats, for it 

 is not likely that these would have been the only mammals that 

 would have wandered there if the islands had ever been a part 

 of the continent. It is hardly likely that the conditions could 

 have been so adverse on the islands, since their supposed separa- 

 tion from the mainland, as to exterminate all but these few re- 

 maining forms. 



The ability of the land tortoises to get to the islands seems to 



3 A Botanical Survey of the Galapagos Islands. Proc.Cal. Acad. Sci., fourth 

 .series, Vol. 1, pp. 7-288, 1911. 



4 /.. c, ])]). 233-243. 



