Tail of Spelerpes fuscus, Bonaparte. 223 
I have studied the habits of sixteen specimens for a period 
of eighteen months, and find that the end of the tail is largely 
used as a tactile organ, and that the terminal half or tiree- 
quarters of an inch is extremely sensitive. 
When climbing they frequently pause and feel about them 
with the end of the tail, using it as an insect uses its antennze 
or as an elephant feels about with the tip of its trunk, In 
this manner they either find something to grasp with the tail, 
or else, satisfied that there is nothing suitable, progress, and 
then again grope about. They are extremely fond of 
climbing the plants of their vivarium, and when doing so 
this method of using their tails is plainly very helpful to 
them ; they grope from side to side in a helpless manner 
when walking up glass. 
Another proof of tactility is that they cannot bear to 
be picked up by their tails or have the end pinched, and fling 
themselves about in the wildest contortions if not imme- 
diately released. 
When taking a prolonged walk Spelerpes fuscus nearly 
always carries the tail clear of the ground, or with at least 
the end portion held well up. This is presumably to keep it 
from becoming callous or injured in any way by obstacles. 
In this the species differs from Plethodon cinereus, of which 
Miss Cochran says * :—‘ The body is not always lifted from 
the ground when the creature is walking—the tail never.” 
I cannot find any other references to this point, but it is 
probable that all the salamanders of this family which 
habitually walk with the tail held up do so for the same 
reasons. 
In the young Spelerpes fuscus the tail is equally sensitive, 
if not more so. One born in my vivarium on May 8th, 1920, 
always lifted its tail off the ground when walking, usually 
with the end curled upwards. As the little creature was 
but 30 mm, long, with a tail 13 mm. long, this method of 
carrying the tail like a retriever spaniel gave it a ludicrous 
appearance. 
Observations of this kind can only be made when the 
Spelerpes are thoroughly awake and active—that is to say, 
after dark, and when the temperature is not too low. At 
such times they are thoroughly alert, as can be seen by their 
rapid and regular respiration. 
I should like to take this opportunity to thank M. G.-F. 
de Witte for his gift of the living specimens from which 
these observations have been made. 
* Biol. Bull. vol. xx, (1911). 
