144 LETTERS ON ENTOMOLOGY. 
fig, or N. opal, from the juice of which it is sup- 
posed to derive its beautiful colour. Perhaps 
the manner in which the Indians reap this curious 
and profitable harvest may amuse you. Round 
their habitations they plant the N. opal, from which 
they expect many crops of the insect in the year. 
The last is gathered when the rainy season ap- 
proaches, for bad weather is very destructive to 
them, and to preserve enough for the next year 
the Indians cut off the leaves on which are the 
young insects, and carry them into their houses 
to keep them dry, and as the leaves are very 
succulent they do not soon wither. The insects 
thus sheltered are nearly arrived at perfection 
when the rainy season is passed. They are then 
in a manner sowed. The Indians make little 
nests of moss, in which they place twelve or 
fourteen insects, and put them between the 
leaves, or as they call them the pencas, sticking 
them on the thorns. In three or four days the 
young ones are born, for we must remark that 
they do not lay eggs like the other gall insects. 
They are produced by thousands, and are, at 
first, no bigger than a pin's point (at least it is 
said so, but we must suppose it rather blunt), 
and soon dispersing in every direction, begin 
sucking the plant in the spot where they fix, 
