144 NORTH AMERICAN INSECTS. 
Southern States could do the same with negro children, as 
well as with the old men and women who havc become in- 
capacitated for hard work. © 
To plant a large number of white mulberry-trees, for the 
purpose of raising silk-worms, is neither difficult nor expens- , 
ive, and whoever raises a large quantity of cocoons may be 
sure of a ready cash sale of them, and at a great profit. 
All the silk and silk-stuffs of commerce originate from 
the common silk-worm ; but there exist several other species 
of nocturnal lepidoptera in America and in Asia, which 
produce silk of a different kind, of which no use, or a very 
limited one, is made; as, for instance, that of the Bombyx 
madrono, mentioned in Humboldt’s travels, which is found 
in the province of Mechoacau, in Mexico, at the height of 
10,500 feet above the level of the sea. Handkerchiefs are 
manufactured of this silk by the inhabitants of Oaxaca. 
The cocoons of the large North American Moths, Cecro- 
pia, Luna, Polyphemus, and Promethea, which I shall il- 
lustrate hereafter, contain much silk, a single fibre of which 
is at least ten times as thick as one of the common silk- 
worm—an experiment I have often made myself. Stuffs 
made out of this silk would far exceed the common fabrics 
in strength and durability, and could not, probably, be worn 
out in many years. 
In India silk is also obtained from the cocoons of other 
Moths, in relation to which Kirby and Spence say: “ Of 
these, the most important species known are the Tusseh and 
Arindy Silk-worms. These insects are both natives of 
Bengal. The first (Attacus papilio, Linn.), feeds upon the 
leaves of the jujube-tree, or Byer of the Hindoos, and upon 
the Terminalia alata glabra, Roxb., the Asseen of the Hin- 
doos, and is found in such abundance as from time imme- 
morial to have afforded a constant supply of a very durable, 
coarse, dark-colored silk, which is woven into a cloth called 
Tusseh-doothies. This fabric is much worn by the Brah- 
