GYMNOTUS ELECTRICUS. 199 
depends upon the will of the creature, and it directs 
it toward the point where it feels most strongly irri- 
tated. The organ acts only under the immediate 
influence of the brain and heart; for, when one of 
them was cut through the middle, the fore part of the 
body alone gave shocks. Its action on man is trans- 
mitted and intercepted by the same substances that 
transmit and intercept the electrical current of a 
conductor charged by a Leyden jar ora Voltaic pile. 
In the water the shock can be conveyed to a con- 
siderable distance. No spark has ever been observed 
to issue from the body of the eel when excited. 
The gymnoti are objects of dread to the natives, 
and their presence is considered as the principal 
cause of the want of fish in the pools of the Llanos. 
All the inhabitants of the waters avoid them; and 
the Indians asserted that when they take young al- 
ligators and these animals in the same net, the latter 
never display any appearance of wounds, because 
they disable their enemies before they are attacked 
by them. It became necessary to change the di- 
rection of a road near Urituco, solely because they 
were sO Numerous in a river that they killed many 
mules in the course of fording it. 
On the 24th March the travellers left Calabozo, 
and advanced southward. As they proceeded they 
found the country more dusty and destitute of 
herbage. The palm-trees gradually disappeared. 
From eleven in the morning till sunset the ther-. 
mometer kept at 95°. Although the air was calm 
at the height of eight or ten feet, the ground was © 
swept by little currents which raised clouds of dust. 
About four in the afternoon, they observed in the 
savannah a young Indian girl, twelve or thirteen 
