THE 
AMERICAN NATURALIST 
VoL. XXXI. August, 1897. 368 
NEW OBSERVATIONS ON THE ORIGIN OF THE 
GALAPAGOS ISLANDS, WITH REMARKS 
ON THE GEOLOGICAL AGE OF 
THE PACIFIC OCEAN. 
By G. Baur, Pu. D., 
ASSOCIATE-PROFESSOR OF PALEONTOLOGY, UNIVERSITY OF CHICAGO. 
In December, 1890, I wrote a paper, “On the origin of the 
Galápagos Islands,’ which was published in the AMERICAN 
Naruraist of March and April, 1891, one month before I left 
for the archipelago. This paper opens with the following re- 
marks: “All islands can be divided into two principal groups : 
1. Islands developed from continents or larger bodies of land 
through isolation or subsidence—Continental Islands. 2. Islands 
not developed from continents, but from submarine coh a 
of the earth— Oceanic Islands. 
“The flora and fauna of the first group will be more or less 
harmonic—that is to say, the islands will be like satellites of the 
continent from which they developed, and the whole group 
comparable to a planetary system. The flora and fauna of the 
second group will be disharmonie—that is to say, it will be com- 
posed of a mixture of forms which have been introduced acci- 
dentally from other places. It is evident the first group of 
! Baur, G. “On the Origin of the Galapagos,” AMERICAN NATURALIST, March, 
1891, p. gm April, 1891, p. 307-326. 
