BLIND CAVE-ANIMALS 325 



or friction in the apertures through which they are 

 forced." 



Another well-known American example is the Wyandotte 

 Cave, traversing the Carboniferous limestone of Crawford 

 County in south-western Indiana. Of this cave, Prof. Cope 

 wrote in 1872 that he was not aware whether its length 

 had ever been accurately determined, " but the proprietors 

 say that they have explored its galleries for twenty-two 

 miles, and it is probable that its extent is equal to that 

 of the Mammoth Cave. Numerous galleries which diverge 

 from its known courses in all directions have been left 

 unexplored." The fact that the blind cave-fish appears to 

 occur in all the subterranean waters flowing through the 

 great Carboniferous limestone region of the central districts 

 of the United States, suggests that the Mammoth and 

 Wyandotte Caves are in communication. Almost equally 

 celebrated are certain caves in the island of Cuba, which 

 are also traversed by subterranean streams. In Europe, 

 perhaps the most interesting cave is that of Adelsberg in 

 Carniola, as being, together with certain other caves in 

 Carinthia and Dalmatia, the sole habitat of that strange 

 creature, the olm or proteus, so graphically described 

 many years ago by Sir Humphry Davy. Although the 

 Carinthian and Dalmatian forms of this creature differ 

 slightly from the Carniolan type, there can be little doubt 

 that the subterranean waters of all the three countries 

 are, or were at a comparatively recent date, in free com- 

 munication. Several caves with the blind fauna are met 

 with in Western Europe, some of the most notable being 

 those in various parts of the South of France ; but the 

 only one in the British Islands is Mitchelstown Cave, near 

 Fermoy, in Ireland, which is excavated in the Carboniferous 

 limestone. 



