| 
THE 
AMERICAN NATU RALIST 
— XXVIII. _ September, 1 "m 333 
ON THE ORIGIN OF THE SUBTERRANEAN FAUNA 
OF NORTH AMERICA. 
Bv ALPHEUS S. Packarp.! 
Having, in my essay on the Cave Fauna of this continent, 
attempted to bring together as many facts as possible bearing 
on this subject, in now addressing the members of this Con- 
gress on the topic assigned me, it will be well to first give a 
résumé of the general subject and then to call attention to the 
additional facts and conclusions relating to this interesting 
topic. 
In that work I took the view that the cave fauna of this 
country, and presumably of the world in general, was formed 
of emigrants or colonists from the surrounding regions of the 
upper world. I may be permitted to give an extract from 
what I published in 1888, in order to call attention to the 
scope of the inqui 
“The conditions of existence in caverns, subterraneous 
streams and deep wells, are so marked and unlike those which 
environ the great majority of organisms, that their effects on 
the animals which have been able to adapt themselves to such 
conditions at once arrest the attention of the observer. To 
such facts as are afforded by cave-life, as well as parasitism, 
the philosophic biologist naturally first turns for the basis of 
1 Read at the meeting of the Zoological Congress of the World’s Auxiliary 
Congress of the Columbian Exposition, Chicago, 1894. 
48 
