162 
NATURAL HISTORY OF 
parts of the body, as well as the legs, are brownish 
black, and covered with pubescence of a somewhat 
lighter hue. 
This insect is pretty widely distributed over the 
intertropical countries of South America, and the 
West Indian islands. When it walks or is at rest, 
the principal light which it emits issues from the 
two yellow tubercles placed at the lateral margins 
of the thorax; but when the wings and elytra are 
expanded in the act of flight, another luminous 
spot is disclosed in the hinder part of the thorax. 
This luminosity is so considerable, that it is often 
employed in the countries where it prevails as a 
substitute fbr artificial lights. A single insect is 
sufficient to enable a person to decipher the 
smallest written character, and when several are 
brought together, their light is said to suffice for all 
the ordinary evening occupations of an Indian's 
dwelling. They are employed for many useful pur- 
poses ; the Indians are said to have formerly used 
them instead of flambeaux in their hunting and fish- 
ing expeditions, and when travelling in the night 
they were accustomed to fasten them to their feet 
and hands. Another important service is rendered 
by these insects in destroying the gnats and mus- 
quitoes, which abound in tropical countries to the 
incessant annoyance of the inhabitants. Like most 
other animals of nocturnal habits, the fire-flies are 
attracted by strong light, and the Indians avail 
themselves of this circumstance to obtain them for 
