2 
THE ART OF REARING 
economy, since some kinds of these beings cause 
even national calamities, while on the contrary 
other species greatly contribute to the prosperity 
of states and individuals. It would be too long, 
and not necessary to the purpose I have in view, 
to enumerate here each family of insects : I shall 
confine myself to observe that those kinds which 
have wings present themselves to us under dif- 
ferent states, in the various periods of their lives, 
and that the faculty of reproducing their species is 
reserved particularly for the last period. Thus 
one sees that, while the butterfly deposits its eggs, 
which are impregnated soon after copulation, these 
eggs do not immediately produce other butterflies, 
but, on the contrary, little animals of a long cylin- 
drical form, composed of a certain quantity of 
segments or rings, having below a certain number 
of feet, of various forms and substances, with other 
particularities which I shall describe afterwards. 
Such, in general, are caterpillars, amongst which 
the silk-worm occupies the first place, and will 
form the subject of the following treatise. 
In this first Chapter I shall make some obser- 
vations, 
1st, On the external and general characters of 
caterpillars. 
2d, On the changes they undergo. 
3d, On their manner of living, their growth, 
and preservation. 
