46 LETTERS ON ENTOMOLOGY. 
A more striking example is given by the oak 
caterpillars, which never separate even in the 
chrysalis state, but live together in families of 
five or six hundred brothers and sisters; they 
eat together, spin together, and repose together ; 
only as butterflies they separate. The order of 
their march is the most remarkable. One goes 
first, and apparently any one who chooses, and 
the rest all follow in regular rows of two, three, 
four, five, &c. : they stop when the leader stops, 
and follow minutely every turn. The order of 
their march is sometimes varied, but always 
regular. Is not this an excellent example of the 
good arising from proper subordination, for how 
else could they continue together ? 
Thus we see how the caterpillars are preserved 
and fed, but we must now consider their enemies 
and misfortunes. When any species multiplies 
exceedingly, nature always provides against its 
superabundance : she produces their enemies in 
equal numbers, and thus the balance is preserved. 
The poor caterpillars in particular have many 
of these; some swallow them at a mouthful, 
others pull them to pieces, and others suck them 
gradually, yet still they are very numerous. 
Though they appear the mildest and most help- 
less of insects, there is one kind winch are quite 
