142 LETTERS ON ENTOMOLOGY. 
LETTER XIV. 
There is something very singular, my dear 
Harriet, in the history of a species, called, by 
Reaumur, Gall insects, from their resemblance 
to galls. At the time of their birth, and for some 
days after, they are extremely small and very 
active, running about the leaves and branches. 
They are then something like small wood lice, 
but they soon fix themselves and remain motion- 
less, and in this inanimate state they increase in 
size prodigiously, and appear like tubercles on 
the back. Some are as large or larger than peas, 
and others as small as grains of pepper. Some 
are circular, others semicircular, and others ob- 
long. They lay thousands of eggs, but keep 
them under their bodies, thus sitting over and 
in a manner hatching them; and when the 
mother dies, which happens soon after, they 
find shelter and safety under the dried shell of 
her body, which remains fastened to the back, 
and serves them as a house, having a little 
glass in one part, which is the door. I have 
