136 
ORIGIN OF LIFE IN AMERICA 
depend upon the testimony based on the remarkably discon¬ 
tinuous ranges of the two recent species. Any theory as to 
the home of the giant, salamanders should be founded on that 
of other animals possessing a similar range. 
The hellbender is not the only large amphibian frequent¬ 
ing the rivers of the eastern States. A somewhat eel-like 
creature, with feeble diminutive limbs and three pairs of 
bushy external gills, inhabits many of the larger streams 
and lakes in the north-eastern States.* It grows to about the 
same length as the giant salamander, but belongs to quite a 
different family. It is commonly known as the “ Mud puppy ” 
(Necturus maculatus), and does not occur west of the Rocky 
Mountains. Now in this case the nearest relation of the east 
American form does not live in Eastern Asia, but, like that 
of the mud minnow (see p. 51), in Eastern Europe. This 
European member of the family Proteidae has manifestly 
undergone a certain amount of degeneration. It possesses 
only three fingers and two toes, is completely blind, and is 
restricted to the subterranean waters of Dalmatia and the 
neighbouring provinces of southern Austria. The “Olm” 
(Proteus anguineus), as it is called, is scarcely a foot long, 
and quite white except for the gill bunches which are 
brilliantly red in colour. It was believed that the Texas 
subterranean newt (Typhlomolge rathbuni) was related to 
the mud puppy. Miss Emerson,f however, has shown that 
it is a salamandrid. No fossil remains of any of these amphi¬ 
bians are known, and any theories as to the origin of the 
discontinuous distribution of the members of this ancient 
family, must be based on zoogeographical data. 
The family of true salamanders and newts (Salamandridae) 
likewise comprises certain members which seem to be of 
very ancient origin, such as the blunt-nosed salamanders 
(Amblystoma). Being only semi-aquatic animals, they 
possess greater facilities for dispersal than the purely fresh¬ 
water forms. Most of them are large species, the tiger sala¬ 
mander (Amblystoma tigrinum) growing to nearly a foot in 
length, and they only repair to the water in the spring to 
* Cope, E. D., “ Batrachia of North America,” p. 26. 
+ Emerson, E. T., “Anatomy of Typhlomolge,” p. 72. 
