202. AFFECTION OF INSECTS FOR THEIR YOUNG. 
naria) the skin of the grains of wheat, in which they respectively deposit 
their eggs, prudently introducing one only into each nut or grain, which is 
sufficient, but not more than sufficient, for the nourishment of the grub 
that will inhabit it. 
II. Hitherto I have adverted to those insects only which perish before 
their young come into existence, and can therefore evince their affection 
for them in no other way than by placing the eggs whence they are to 
spring in secure situations stored with food ; and these include by far the 
largest portion of the race. A very considerable number, however, extend 
their cares much further : they not only watch over their eggs'after deposit- 
ing them, but attend upon their young when excluded, with an aifectionate 
assiduity equal to any thing exhibited amongst the larger animals, and in 
the highest degree interesting. Of this description are some solitary 
insects, as several species of the Linnean genus Sphex, earwigs, field-bugs, 
and spiders: and those insects which live in societies, namely, ants, bees, 
wasps and termites: the most striking traits of whose history in these 
respects I shall endeavour to lay before you. 
You have seen that the greater number of the Sphecina, after depositing 
their eggs in cells stored with a supply of food, take no further care of 
them. Some, however, adopt a different procedure. One of these, called 
by Bonnet the Mason-wasp, but different from Reaumur’s, not only incloses 
a living caterpillar along with its eggs in the cell, which it carefully closes, 
but at the expiration of a few days, when the young grub has appeared 
and has consumed its provision, re-opens the nest, incloses a second cater- 
pillar, and again shuts the mouth : and this operation it repeats until the 
young one has attained its full growth.‘ A similar mode, according to 
Rolander, is followed by Ammophila vulgaris, as well as by the yellowish 
wasp of Pennsylvania, described by Bartram in the Philosophical T'ransac- 
tions, and by another related to Mellinus arvensis, observed by Duhamel*; 
both of which, however, instead of caterpillars, supply their larve: with a 
periodical provision of living flies. 
What a crowd of interesting reflections are these most singular facts cal- 
culated to excite! With what foresight must the parent insect be en- 
dowed, thus to be aware at what period her eggs will be hatched into 
grubs, and how long the provision she has laid up will suffice for their 
support! What an extent of judgment, thus, in the midst of various other 
occupations, to know the precise day when a repetition of her cares will 
be required! What an accuracy of memory to recollect with such pre- 
cision the entrance to her cell, which the most acute eye could not dis- 
cover; and without compass or direction unerringly to fly to it, often from 
a great distance, and after the most intricate and varied wanderings! If 
we refer the whole to instinct, and to instinct doubtless it must in the main 
if not wholly be referred, our admiration is not lessened. Instinct, when 
simple and directed to one object, is less astonishing ; but such a compli- 
cation of instincts, applied to actions so varied and dissimilar, is beyond 
our conception. We can but wonder and adore! 
The female of Perga Lewisii (Westwood), one of the Tenthredinide, or 
Saw-flies, was observed by Mr. Lewis at Hobarton, Van Diemen’s Land, 
to sit upon the leaf into which she has inserted her eges, about eighty in 
1 Bonnet, ix, 898, 2 liii, 37, Pelopaus spirifex? 3 Reaum. vi, 269. 
