228 NATURAL HISTORY OF WASPS. 
chop their food smaller still. For he has seen the adult 
wasps supplying the larvee with masses of solid food 
of such a size as to require to be cut up into smaller 
pieces before they could be swallowed.* If the 
benefit of insects to man is to be measured by the 
number of other insects that they destroy, wasps 
must be our benefactors indeed. 
When the perfect insect leaves its cell it leaves its 
prison history written on the walls in very plain cha- 
racters. Here is the egg-shell, wanting only a little 
patience to spread it out in its full proportions. 
Here, close by, is the first skin, at once distinguished 
by the great length of the central tooth of the man- 
dibles. Pressed down upon these relics of an earlier 
age, earlier by a fortnight perhaps, is the spiral coil 
of undigested food wrapped in its own membranes, 
a daily record of all that the little grub has eaten, 
or rather has failed to digest. On this lies the 
second skin and its mandibles, needing a great deal 
of patience to disentangle it perfectly ; and on this, 
again, we may find as much of the cast skin of the 
pupa as has not been either swallowed by the insect 
just emerging into active life, or picked out of the 
deserted cell piecemeal by her elder sisters. And 
this story is repeated, in the same way, as many times 
as the cell has been occupied; egg-shell, first skin, 
excreted mass, second skin, and shreds of pupal 
investment lie in sets, in the same order as they 
have been cast off by each successive tenant. 
There has long been a discrepancy of opinion 
* Wildman, ‘A Treatise on the Management of Bees,’ &. 4to. — 
London, 1768, p. 158, “so large that they were scarce able to swallow 
“them.” 
