24 
MEMOIBS OF THE NATIONAL ACADEMY OF SCIENCES. 
this peculiar troglodyte assemblage, need uot demand the “numberless generations” insisted on by 
Mr. Darwin in his Origin of Species. The time since the present climatic relations aud the present 
fauna came into existence may, it seems to us, be estimated by a few thousands rather than by 
hundreds of thousands of years. 
It should be borne in mind that early in the Eiver Terrace epoch, when the cavernous region 
was flooded, no life could have existed in these caves. Even now that extensive cavern, Howe’s 
Cave, excavated from the Silurian limestone in Schoharie county, New York, is said to have no 
life in it except a few common crickets (Geuthophilus maculatus ), found everywhere in New York 
aud New England under stones and logs. In his excellent account of Howe’s Cave, through 
which a stream runs, Bev. Mr. Hovey remarks: 
Bat the guide assured me that during a rainy season * * * there were times when the whole cavern would 
be filled and, as he said, “ pour forth a mighty flood.” 
Again, on page 195, he says: 
The swiftness of the cave stream and its liability to sudden overflow have prevented the aborigines from making 
this cavern a place either of residence or sepulture. It may be doubted, indeed, if they knew of its existence. Few 
animal remains have been found here. Large numbers of bats, however, hibernate in its chambers, clinging in 
clusters, like swarms of bees. No fish inhabit the lake or the stream, except such as have been put there by the hand 
of man, and even these forsake these subterranean waters when the spring freshets give them the opportunity to do so. 
It is noteworthy that in glaciated regions the few caves in existence, of which Howe’s Cave is 
the largest kuown to us, do not support a true cave fauna. In Europe the Carniolan aud Pyrenean 
region may have been glaciated, but we infer not. In the United States, at all events, the cavernous 
regions of southern Indiana, Kentucky, Tennessee, and Virginia lie south of the great moraine. 
It is plain enough that the caves of Oarniola and other portions of Austria and of Illyria, as well 
as the caves of Basse-Pyrenees in France and the caves of Spain, have been colonized from members 
of the existing fauna, which was derived mainly from the shores of the Mediterranean, and are 
warm, temperate in their complexion, belonging to the Mediterranean sub region. 
THE SOURCE OF THE FOOD SUPPLY OF CAVE ANIMALS. 
So far as observed cave animals, even the carnivorous species, take remarkably little food, and 
the source of the food supply in caverns is naturally a question of much interest. As regards the 
voracity of the blind-fish (Amblyopsis spelceus), several of which I had the pleasure of seeing in 
Dr. John Sloan’s aquarium, he wrote me as follows, under date of May 9,1875: 
I have some large blind-fishes which I put in my aquarium in August, 1873. They have taken no food, except 
what has grown up in the water and on the sand in their tank. Are they nourished by the confervoid and animalcul® 
growth ? 
This quotation will also give proofs that this blind-fish may be readily kept for over a year in 
a large aquarium, the one in question having stood in a well-lighted room in Dr. Sloan’s house. 
It is, however, known that an Amblyopsis, in one case at least, swallowed a fish with eyes, as 
Dr. Wyman found in 1856, in the stomach of an Amblyopsis he was dissecting, a small fish figured 
by Professor Putnam (Amer. Naturalist, Jan. 1872, PI. I, fig. 13). 
Without much doubt the natural food of the blind-fish, besides an occasional young fish of 
its own or some other species, is the blind crayfish, as well as Crangonyx, and perhaps the Oseci- 
dotsea, though the latter usually lives concealed under stones. 
The food of the blind crayfish appears to consist of living Csecidotaea. Mr. Moses N. Elrod, of 
Orleans, Orange county, Indiana, writes me as follows regarding this point under date of June 4, 
1873: 
Since writing the above I have collected over a hundred Csecidotaea and a number of other forms (Crangonyx) 
from a well in town. They were iu and on the bucket, that had been in the bottom of the well for several days. I also 
have a live eyeless crayfish taken from one of our own wells yesterday, and have fed the Csecidotaea to it. If the 
Cmcidotsea are put near, in its claw, it eats them almost instantly. I am trying the blind-fish to see if they will eat 
them. I have three live blind-fish in my cellar, one as large as they ever grow, and I think it a female. 
The blind crayfish, then, appears to prefer living small Crustacea, and is not omnivorous in its 
appetite. Eegardiug this point Mr. Putnam remarks as follows: 
Many of the specimens [of 0. pellucidas ] were brought alive to Massachusetts, and several still continue in good 
condition, though they have eaten very little since their capture. I have several times offered them food in the shape 
