LETTERS ON ENTOMOLOGY. 
53 
amining the cloth with a microscope, many red, 
blue, or green hairs have been discovered mixed 
with the others. They cause more destruction 
by mowing, as it were, the long hairs which ob- 
struct their passage, than by what they eat. 
Finally, when they have attained their full 
size, and the time of their metamorphosis ap- 
proaches, they forsake the cloth they have lived 
on, and seek a more fixed and safe asylum. They 
fasten themselves in the angles of walls and the 
crevices of furniture, sometimes by one end, and 
sometimes by both, which they always close by 
a silken tissue. Thus inclosed, the caterpiDar 
soon turns to a chrysalis, which gradually changes 
from light yellow to a reddish colour; and 
finally, in about three weeks, comes out a little 
gray moth. 
If these larvae are shut up with dead butter- 
flies, they make very pretty garments of the hair 
and pieces of the wing. 
It is worthy of remark, that they never attack 
wool that is not cleansed of grease, and they dis- 
like any powerful smell. A fumigation of tobacco 
is fatal to them. 
There is another of the same species which 
lives in the woods, fields, or gardens, and feeds 
on the leaves. These do not clothe themselves 
