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 he 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 $ 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 and 
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, C., “Journal of Researches,” p. 142. 
t Newton, E. T., “ Fossils from Falkland Islands,” p. 251. 
t Vallentin, R., “ Voyage to the Falklauds,” p. 352. 
§ Lydekker. R., “ Geographical History of Mammals,” p. 140. 
|| Ihering, II. von, “ Verbreitung d. Siidamerik. Raubtiere,” p. 153. 
