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 actually find to be the case. 



Another fact of interest in this connection is the circumstance 

 that these cave species breed slowly, 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 would 

 probably starve, as the supply of food even for those which do 

 live is wonderfully limited. 



It is now known that animals inhabiting the abysses 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 questions 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. Since my article was printed, Prof. Cope's article entitled "Life in the Wyan- 

 dotte Cave" has appeared in the "Annals and Magazine of Natural History" (Lon- 

 don) for November. He enumerates the following articulates as inhabitants of this 

 cave; " Anophtlialmus Telllcampfii, and another species; two species of Staphylinidae; 

 Raphidophora ; two species of flies; an Aranea-like and Opiliolike spider; a species of 

 Pseudotremia; Cambarus pellucidus, an unknown aquatic Crustacean with external 

 egg pouches, and a Lernsean (crustacean) parasitic on the blind fish. Of these one 

 beetle (Anophtlialmus), 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 different from those of the 

 latter, and the centipedes are much more numerous. The Gammaroid crustarean 

 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. 



