No. 399. ] THE SAN MARCOS SALAMANDER 181 
In water, however, the weight of the salamander is so little 
that the legs are amply strong for its locomotion. Professor 
Stejneger lost sight of this point when he guessed that the 
animal used its tail for locomotion and its legs as feelers, for 
he says: ‘Viewed in connection with the well-developed, 
finned swimming-tail, it can be safely assumed that these 
extraordinarily slender and elongated legs are not used for 
locomotion, and the conviction is irresistible that in the inky 
darkness of the subterranean waters they serve the animal as 
feelers.”’ 
No definite information has been obtained as to their habits 
in nature, 
They show no reaction against light, either as a response by 
motion to the direction of the rays or to the quantity of light. 
Fic. 2.— The same as Fig. 1, but from above. 
If kept in a vessel, one-half of which is dark and the other half 
light, the animal is found about as much in one as the other, 
and on emerging into light from the dark half indicates in no 
way an awareness of the difference. 
If in a tangle of plants, as watercress, they are found there 
about the same as in any other part of the vessel. 
If they are headed against a current, the flowing water acts 
as stimulus urging them on. If the current strikes them from 
behind, they move more rapidly in the direction of flow. 
The sense of touch is highly developed. There is, however, 
no experimental evidence that this is confined to any particular 
region. If the surface of the body is touched anywhere except 
at the blunt truncated snout, the animal responds at once by 
moving away. If the stimulus causes it to swim away, it may 
