182 THE AMERICAN NATURALIST. [Vor. XXXIV. 
go (say 12 or 16 inches) till it strikes the side of the vessel, 
after which it soon comes to a standstill. 
If, however, it is struck say with the flat side of a scalpel 
handle sufficiently hard to move the entire animal even an inch 
backwards, it may not react, and this may often be repeated 
FiGs. 3 and 4. 
Fic. 3. — Dorsal surface of a salamander Pastors in formalin. 
Fic. 4. — Ventral surface of the same specimen. 
before it reacts by moving away. A possible explanation of this 
is that in normal life it is every day striking itself against obstacles, 
especially the sides of the vessel (when in confinement). 
The animal was kept in water about an inch deep, so that 
its head was near the surface. The waves of the water set 
going by a gentle puff of the breath act as a sure stimulus. It 
is exceedingly sensitive to any motion of the water. 
