28 
ORIGIN OF CAVE LIFE. 
whose habits varied, as those of their out-of-door allies do at pres- 
ent. Had they been specially created for subterranean life, we 
should have expected a much greater uniformity in the organs 
adapting them to a cave life than we actuall}^ find to be the case. 
Another fact of interest in this connection is the. circumstance 
that these cave species breed slowl}^, being remarkably poor in in- 
dividuals ; they are nearly all extremely rare.^ Did they breed as 
numerously as their allies in the outer world the whole race Avould 
probably starve, as the supply of food even for those which do 
live is wonderfully limited. 
It is no V known that animals inhabiting the abj-sses of the sea are 
often highly colored : light must penetrate there, for we know that 
were the darkness total they would be colorless like the cave insects. 
In view of the many important C|uestions which arise in relation 
to cave animals, and which have been too imperfectly discussed 
here, we trust naturalists the world over will be led to explore 
caves with new zeal, and record their discoveries with minuteness, 
and the greatest possible regard to exactness. The caves of the 
West Indian Islands should first of all be carefully explored. 
Also those of Brazil, those of the East Indies and of Africa, 
while fresh and most extended explorations of our own Mammoth 
Cave should be made, perhaps by a commission acting under gov- 
ernment or State authority, in order that the most ample facili- 
ties may be afforded by the parties owning the cave. 
Note. — Siuce my article was printed. Prof. Cope’s article entitled ‘‘Life in the Wyan- 
dotte Cave” has appeared in the “Annals and Magazine of Natural Histoi-y” (Lon- 
don) for November. He enumerates the following articulates as inhabitants of this 
cave; Anoplithalmus TeWcampfii^ unA another species; two species of Staphylinidae; 
Raphidophora; two species of flies; an Aranea-like and Opilio-like spider; a species of 
Pseudotremia; Cambarns pellucidus, an unknown aquatic Crustacean with external 
egg pouches, and a Lernaean (crustacean) parasitic on the blind fish. Of these one 
beetle (Anophthalmus), the cricket (Raphidophora), a fly, the Opilio-like spider, the cen- 
tipede, and the blind crawfish, are probably the same as those found in the Mammoth 
Cave. Two beetles and two crustaceans are certainly difl'erent from those of the 
latter, and the centipedes are much more numerous. The Gammarokl crustacean 
found in the waters of the Mammoth Cave, and which is, no doubt in part, the food of 
the blind fish, we did not find; but some such species no doubt exists, as we found an 
abundance of a lively little tetradecapod crustacean near the mouth of a cave close by.” 
* The wingless grasshoppers are common however, and Prof. Hagen writes me that 
the cave insects in Europe are probably not so rare as they are thought to be by natu- 
ralists, since the guides do not show the best collecting places, wishing to keep a stock 
on hand to sell to visitors. 
