906 The American Naturalist. [October, 
exceedingly difficult to reach the places where they live. We secured 
eight living ones, of different size: five with shells one meter or more 
in length, and one, probably the largest one ever taken from the 
islands, with the carapace one meter and forty centimeters in length. 
You may imagine the amount of work when I tell you that these speci- 
mens had to be carried from eight to twenty miles over the lava fields 
and through the densest brushwood. 
I do not need to say that there was no possibility of bringing the large 
tortoises down alive. The largest one must have had a weight of 400 
pou On Duncan we secured eight tortoises; they are much 
smaller than the forms from South Albemarle, and resemble the 
Abingdon specimens, On the northeast side of Albemarle I tried to 
penetrate to the interior, but had to return after two days on account 
of the nearly impassable lava fields. 
So far I can say that the expedition has had the greatest success, 
and I am convinced that my expressed opinion on the origin of this 
group of islands is the correct one. I may add that in a single 
instance (near Barrington) I have found a land bird flying over the 
ocean ; it was the common Dendreca aureola, found on all islands. 
It is certain, therefore, that these birds do not travel from one island to 
the other, as is also fully sustained by the collections. 
The birds are still as tame as formerly, especially on such islands 
which are not often visited. On Duncan a Buteo galapagoénsis sat 
down on a bush next to me, I touched him with a stick; he did not 
move. I began to tickle him on the head; this he seemed to like ; 
and an hour later, when I had gone to a smaller island near that place, 
he also came over and sat down next to me to be tickled by the stick. 
Myiarchus is the tamest bird, and often sat down on my hat or my 
stick when I kept quiet. 
` I finish this letter, hoping that the expedition will be followed by 
others of the same nature. Biology is of the greatest importance for 
dynamical geology, and is in many cases the only source of informa- 
tion. The Fiji or Friendly Islands, which are considered as oceanic 
islands, but which I believe to be continental, ought to be examined, 
and also a group of islands which is doubtless of oceanic origin. 
Harmony or disharmony in the distribution of flora and fauna will 
always, I think, solve the problem of the origin. That variation goes 
on in definite lines, determined by the nature of the conditions, I am 
fully convinced. The theory of natural selection, especially the 
view of the ‘‘ Neo- Darwinians,”’ has not received any support; but 
more about this question later. - 


