mortar, thrust
outward from within. This forms the irregular nipple which projects from
the side of the shell.

For the present I shall not expatiate further upon Stizus ruficornis,
whose complete biography would be out of place in this chapter. I will
limit myself to mentioning its method of constructing strong-boxes in
order to compare it with that of the Bembex and above all with that
of the Tachytes, a consumer, like itself, of Praying Mantes. From this
parallel it seems to me to follow that the conditions of life in
which men see to-day the origin of instincts--the type of food, the
surroundings amid which the larval life is passed, the materials
available for a defensive wrapper and other factors which the
evolutionists are accustomed to invoke--have no actual influence upon
the larva's industry. My three architects in glued sand, even when all
the conditions, down to the nature of the provisions, are the same,
adopt different means to execute an identical task. They are engineers
who have not graduated from the same school, who have not been educated
on the same principles, though the lesson of things is almost the
same for all of them. The workshop, the work, the provisions have not
determined the instinct. The instinct comes first; it lays down laws
instead of being subject to them.

CHAPTER 7. CHANGE OF DIET.

Brillat-Savarin, when pronouncing his famous maxim, "Tell me what you
eat and I will tell you what you are," certainly never suspected the
signal confirmation which the entomological world would bestow upon his
saying. Our gastrosopher was speaking only of the culinary caprices of
man rendered fastidious by the sweets of life; but he might, in a more
serious department of thought, have given his formula a wider and more
general bearing and applied it to the dishes which vary so greatly
according to latitude, climate and customs; he might above all have
taken into his reckoning the harsh realities suffered by the common
people, when perhaps his ideal of moral worth would have been found in
a platter of chick-peas oftener than in a pot of pate de foie gras. No
matter: his aphorism, the mere whimsical sally of an epicure, becomes an
imperious truth if we forget the luxury of the table and look into what
is eaten by the little world which swarms around us.

To each its mess. The cabbage Pieris consumes the pungent leaves of the
Cruciferae as the food of her infancy; the Silkworm disdains any foliage