430 ORIGIN OF LIFE IN AMERICA 



grass with a growth of bushes here and there. As Darwin 

 pointed out long ago, almost the whole of the islands are com- 

 posed of sedimentary rocks, such as clay-slate and sandstone, 

 while the hills are formed of white granular quartz. Darwin* 

 considered the sandstone of Silurian age, whereas Mr. 

 Newton,f who has recently examined the fossils brought back 

 by Dr. Bruce, shows that they belong to the Devonian Period, 

 many of them being identical with South African species of 

 similar age. 



No clue, however, can be obtained from the geological fea- 

 tures as to the age of the islands, or, as we might say, the 

 time when the latter became separated from the mainland. 

 We are thus obliged to seek for information from the exist- 

 ing animals and plants. Mr. Vallentin's J account of the 

 fauna and flora only deals with the general features, such as 

 a casual visitor might notice. He informs us that no indi- 

 genous mammals occur on the Falkland islands, as the peculiar 

 wolf (Canis antarcticus) which once lived there is now ex- 

 tinct. It is still customary to connect this Falkland island wolf 

 with some of the mainland species, although Mr. Lydekker 

 pointed out long ago that it differs markedly from all the dog- 

 and wolf -like creatures (Canidae) of South America, being 

 closely allied to the North American coyote (Canis latrans). 

 Dr. von Ihering || places it, along with the coyotes, into the 

 sub-genus Lyciscus, whereas the remaining South American 

 species of the family belong to Chrysocyon, Carcinocyon ami 

 other genera. Neither of these writers dwell upon the causes 

 of this altogether extraordinary range. Are we to regard this 

 as an instance of convergence ? I scarcely think that any 

 mammalogist will maintain such a view. And yet how are we 

 to account for the fact of the existence in these remote islands 

 of a mammal whose nearest relatives are all confined to North 

 America ? It is an extremely interesting problem. I have 

 alluded to the noteworthy fact more than once that Chile, and 

 even Tierra del Fuego and Argentina, exhibit a very surprising 



* Darwin, 0., "Journal of Researches," p. 142. 



t Newton, E. T., " Fossils from Falkland Islands," p. 251. 



t Vallentin, E,, " Voyage to the Falklands," p. 352. 



Lydekker. E., " Geographical History of Mammals," p. 140. 



|| Ihering, H. von, " Verbreitung d. Siidamerik. Eaubtiere," p. 153. 





