All day long they writhe and wriggle in a swarm, although perfectly free to escape; numbers perish in the tumultuous orgy.

They are not retained by the desire of food, for the arum provides them with nothing eatable; they do not come to breed, for they take care not to establish their grubs in that place of famine.

What are these frenzied creatures doing?
Apparently they are intoxicated with fetidity, as was Bull when he rolled on the putrid body of a mole.
This intoxication draws them from all parts of the neighbourhood, perhaps over considerable distances; how far we do not know.

The Necrophori, in quest of a place where to establish their family, travel great distances to find the corpses of small animals, informed by such odours as offend our own senses at a considerable distance.
The _Hydnocystis_, the food of the Bolboceras, emits no such brutal emanations as these, which readily diffuse themselves through space; it is inodorous, at least to our senses.

The insect which seeks it does not come from a distance; it inhabits the places wherein the cryptogam is found.