Vor. II, Pr. II] WHEELER—GALAPAGOS ISLANDS ANTS 265 
can be adduced in support of the subsidence or “‘continental’’ 
as for the emergence or “oceanic” origin of the archipelago. 
So evenly divided are the authorities that 19, namely, Dar- 
win, Wallace, Hooker, A. Agassiz, Salvin, Griesebach, 
Engler, Moritz Wagner, Peschel, Wolf, Dall, Stewart, 
Stearns, Snodgrass, Heller, Robinson, Williams, McNeill and 
Matthew, have expressed themselves in favor of the “oceanic” 
hypothesis, while an equal number, namely, H. Milnes Ed- 
wards, Murray, Baur, Hemsley, Ridgway, Robinson and 
Greenman, Boetger, von Ihering, Handlirsch, Scharff, Ort- 
mann, Ratzel, Gunther, Sarasin, Gadow, Arldt, Barbour, and 
Van Denburgh, have expressed themselves as favoring a 
“continental” origin of the archipelago. Eleven other work- 
ers who have studied material from the islands, namely 
Banks, Coquillet, Currie, Heidemann, Kellogg, Gifford, 
Linell, Howard, Garman, Rothschild and Hartert, have not 
committed themselves to either hypothesis. Some of the 
authors who take sides in the controversy are evidently 
influenced by the fancied facilities afforded by their special 
groups of organisms for transportation by winds or currents 
from the western coast of South or Central America. The 
botanists find it easy to suppose that seeds and the spores of 
ferns have thus found their way to the islands, while herpetol- 
ogists balk at postulating such means of transportation for 
the huge land tortoises which have been so carefully studied 
by Baur and by Van Denburgh. At least one of the authors, 
Robinson, has changed his views in the course of his studies. 
In his first paper on the flora, written in collaboration with 
Greenman™, he favored the Murray-Baur hypothesis of a 
continental origin of the islands, but in a more voluminous 
work’, based on additional collections, he returns to the 
older Darwin-Wallace hypothesis. Some authors, like 
Stearns, Dall** and Stewart, make much of the “flotsam 
and jetsom” origin of the Galapagos fauna and flora, whereas 
11 Robinson, B. L., and Greenman, J. M. On the Flora of the Galapagos Islands 
as shown by the collections of Dr. G. Baur. Amer. Journ. Sci., 50, 1895, pp. 135-176. 
12Robinson, B. L. Flora of the Galapagos Islands. Papers from the Hopkins 
Stanford Expedition to the Galapagos Islands. Proc. Amer. Acad, Arts and Sci. 38, 
1902, pp. 77-269, 3 pls. 
133 Stearns, R. E. C. Report on the Mollusk Fauna of the Galapagos Islands, 
with Descriptions of New Species. Proc. U. S. Nat. Mus. 16, 1893, pp. 353-450. 
14 Dall, W. H. Insular Landshell Faunas, Especially as Illustrated by the Data 
Obtained by Dr. G. Baur in the Galapagos Islands. Proc. Acad. Nat. Sci., Phila., 
1896, pp. 395-459, 3 pls. 
