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. 
