1891.] The Origin of the Galapagos Islands. 311 
Revilla Gigedos are nothing buta part of the American continent ; 
they are also, like the Galapagos, within the 4000 m. line. 
South of the Galapagos we have the islands Felice and Juan 
Fernandez, with their peculiar flora and fauna. It is not possible 
to determine whether there has been any connection between these 
islands and the Galapagos, but the fact that we find on the 
Galapagos three forms of Antarctic animals, which reach the most 
northern limit in this group, is to be mentioned. These animals 
are the Otaria jubata, Arctocephalus australis, and the peculiar 
penguin, Spheniscus mendiculus Sundev., only found on the 
Galapagos. Another interesting point is that the albatross, which 
” so far as I know has only been described as breeding from the 
southern islands, especially Tristan daCunha, breeds on Hood's 
Island, as observed by Delano and Wolf. 
Much work remains to be done. A great number of systematic 
deep-sea soundings have to be made between these different 
groups of islands and the continent. And the islands themselves 
have to be examined very carefully. We know nothing at all 
about the fauna and flora of the isolated Clipperton Island and 
Malpelo; we hardly know anything about Cocos Island, which 
seems to be in many respects quite different from the others, 
having a more tropical appearance. An enormous and highly 
interesting field of research is here open. After all this has been 
done, we may be able to discuss fully the question of the 
connection of the different islands. One thing, however, we 
assume to-day: the probability of the origin of the Galapagos 
through subsidence. But if this be probable for the Galapagos, 
how is it with the Sandwich Islands, for instance; so far as they are 
known they seem to be of the same harmonic nature in flora and- 
fauna. Have they not originated in the same way ? How about 
the other islands in the Pacific, and how about the theory of the 
consistency of the Pacific Ocean? Is this theory really estab- 
lished on a sound basis ? | 
We now ‘come to another very important question, What is 
the reason of the variation of the forms on the different islands ? 
In other words, What is the origin of the different species of the 
different Tos ? 
