206 
ANIMAL CURIOSITIES 
inhabiting the depths of the subterranean 
streams—the capture of its prey being rendered 
more easy owing to its mouth being directed 
upwards in such a manner that, when the fish 
makes a bite, it has not to poise itself so 
obliquely beneath its prey as other surface¬ 
feeding fish have to do. Its head, moreover, 
is very flat at the top, thereby enabling the 
creature to swim quite near to the surface, 
ready to snap up anything that may come 
within its reach. 
In one respect, however, its surface-feeding 
habits are detrimental to its welfare, for the 
fish is quite easy to catch with a net or even in 
one’s hand, although complete silence must be 
kept, otherwise it will promptly dive down to 
the depths and disappear from view. 
Other fish that share with the foregoing the 
inability to see are the blind soles, of which 
there are two different kinds. In both the eyes 
are rudimentary, and the pectoral or breast 
fins are absent. 
Also inhabiting the waters of underground 
caves is a curious batrachian called the olm 
or proteus. Found in Dalmatia, Carinthia and 
Carniola, the creature grows to a length of 
about eighteen inches, and possesses a long, 
slender and snake-like body which terminates 
in a vertically-flattened tail. The tiny limbs 
