Do the husband and wife recognize each other among their fellows? Are they mutually faithful? Cases of breach of matrimony are very rare, in fact unknown, on the part of the mother, who has long ceased to leave the house; on the other hand, they are frequent on the part of the father, whose duties often oblige him to come outside. As will be seen presently, he is, throughout his life, the purveyor of victuals and the person entrusted with the carriage of the rubbish. Alone, at different hours of the day, he flings out of doors the earth thrown up by the mother’s excavations; alone he explores the vicinity of the home at night, in quest of the pellets whereof his sons’ loaves shall be kneaded. Sometimes, two burrows are side by side. Cannot the collector of provisions, on returning home, easily mistake the door and enter another’s house? On his walks abroad, does he never happen to meet ladies taking the air who have not yet settled down; and is he, then, not forgetful of his first mate and ready for divorce? The question deserved to be examined. I tried to solve it in the manner that follows. Two couples are taken from the ground at a time when the excavations are in full swing. Indelible marks, contrived with the point of a needle on the lower edge of the elytra, will enable me to distinguish them one from the other. The four subjects of my experiment are distributed at random, one by one, over the surface of a sandy area a couple of spans thick. A soil of this depth will be sufficient for the excavations of a night. In case provisions should be needed, a handful of sheep-droppings is served. A large reversed earthen pan covers the arena, prevents escape and produces the darkness favourable to mental concentration. The next morning provides a splendid response. There are two burrows in the establishment, no more; the couples have formed again as they were: each Jack has his Jill. A second experiment, made next day, and a third meet with the same success: those marked with a point are together, those not marked are together, at the bottom of the gallery. Five times more, day after day, I make them set up house anew. Things now begin to be spoilt. Sometimes, each of the four that are being experimented on settles apart; sometimes, the same burrow contains the two males or the two females; sometimes, the same crypt receives the two sexes, but differently associated from what they were at the start. I have abused my powers of repetition. Henceforth disorder reigns. My daily shufflings have demoralized the burrowers; a crumbling home, always requiring to be begun afresh, has put an end to lawful associations. Respectable married life becomes impossible from the moment when the house falls in from day to day.