Let us make an attempt or two, however.

I scoop in a log of fresh cypress-wood a groove of the same diameter as that of the natural galleries and I place the worm inside it.

Cypress-wood is strongly scented; it possesses in a high degree that resinous aroma which characterizes most of the pine family.

Well, when laid in the odoriferous channel, the larva goes to the end, as far as it can go, and makes no further movement.

Does not this placid quiescence point to the absence of a sense of smell?
The resinous flavour, so strange to the grub which has always lived in oak, ought to vex it, to trouble it; and the disagreeable impression ought to be revealed by a certain commotion, by certain attempts to get away.