ANIMALS. 
213 
any one locality on the Isthmus. On the Atlantic plains Mus- 
quitos are very numerous, particularly on the low lands bor- 
dering the streams, where the dense foliage affords them pro- 
tection from the winds and rains ; but wherever the country is 
cleared up to any extent, so as to give the air free circulation, 
they are not reproduced so abundantly. The villages being 
uniformly located on elevated ground but partially sheltered by 
trees, the inhabitants experience very little inconvenience from 
these insects. Going southerly, the Musquitoes mostly disappear 
at the Jaltepec River, and in their place we have the Rodadors, 
or Buffalo Gnats, which are very numerous between this river 
and the plains of Xochiapa. South of these plains there are no 
Rodadors or Musquitoes, but more or less Garrapatas, Chigoes, 
Fleas, Centipedes, Scorpions, &c. 
The Rodadors, though confined to less than one-third the 
breadth of the Isthmus, are exceedingly troublesome, their bites 
being more poisonous than that of the Musquito, and swarming 
in such immense numbers that it is very difficult guarding 
against their attacks. The inhabitants of the country, however, 
seem to disregard their bites altogether. This insect possesses 
one redeeming quality not exhibited by the Musquitoes, inas- 
much as it suspends offensive operations during the night : it is 
a singular fact, that only the females exhibit these biting pro- 
pensities. The Chaquiste is a species of gnat, smaller than the 
Rodador ; and the Gegin is a still smaller variety, found only on 
the Gulf and Pacific coasts. The Garrapatas are a very large 
species of tick, which are particularly troublesome to horses, 
and are common on all parts of the Isthmus. The Pinolilk- 
is a diminutive variety of the same species. The Chigoe 
{Pulex penetrans) is a very troublesome insect. It is an ex- 
tremely small, black flea, which usually attacks the feet, insinu- 
ating itself under the skin so gently as not to be noticed, where, 
if not soon removed, it raises a numerous progeny, and if neg- 
lected for a long time, sometimes produces incurable ulcers. A 
most frightful case came under our notice while on the Isthmus 
in the person of a gray-headed Indian, who had been afflicted 
with it for more than twenty years ; in him it was accompanied 
by Elephantiasis. His legs were swollen to more than three 
