A week or so passes. The male reappears on the surface; he is restless, he makes desperate efforts to climb out; the relations are done, quite done; he wants to get away. By and by, the female comes up in her turn; she tries the nearest cake, picks the best of it and takes it underground. She is building her nest. As to her companion, he does not even notice what is happening: these things do not concern him.
The other captives, of no matter what species, when consulted in the same manner, give the same reply. The Onthophagus tribe knows nothing of household ties.
In what respect are those who know them and who observe them so faithfully any the better off? I do not quite see; or, to be more candid, I do not see at all. [[268]]If, in the case of the Geotrupes, I see in the bulky pudding some slight excuse for the collaboration of the father, who is a valuable assistant in the fabrication of this kind of preserve, and if, in that of the Minotaur, the immensely deep well might suggest to me the need for the trident-wearing helper, who shoots out the rubbish while the mother goes on digging, I should still be without an explanation when I came to the Sisyphus, who is very economical both in provisions and in the labour of excavation and requires no help with either. I will not deny that, in this last case, the male is of some use, watching over the pill, lending occasional help and encouraging the female with his presence; but, after all, the part which he plays as a collaborator is a very secondary one, and the mother, one would say, could do without any assistance, as is the rule among the Scarabæi. Here, besides, we have the Bull Onthophagus, who is even smaller than the Sisyphus; and this dwarf, unacquainted with a partnership that would increase her powers twofold, fulfils a task which is almost equivalent to that of the Beetles who roll their pills in double harness.
Then how are talents and industries distributed? If we go on accumulating fact upon fact, observation upon observation, shall we ever come to know? I venture to doubt it.
I have friends who sometimes say to me:
‘Now that you have collected such a mass of details, you ought to follow up analysis with synthesis and promulgate a comprehensive theory of the origin of instincts.’
There’s a rash proposal for you! Because I have turned over a few grains of sand on the seashore, am I qualified to talk about the ocean depths? Life has its unfathomable secrets. Human knowledge will be struck [[269]]off the world’s records before we know all that is to be said about a Gnat.
Equally obscure is the question of nest-building. By a nest we understand any residence constructed purposely to receive the eggs and to protect the development of the young. The Bees and Wasps excel in the art. They know how to make cabins out of cotton-stuffs, wax, leaves or resin; they build turrets of clay and domes of masonry; they mould earthenware urns. The Spiders vie with them. Remember the flying-machines, the rose-patterned paraboloids of certain Epeiræ; the globular bag of the Lycosa; the Labyrinth Spider’s cloisters with their Gothic arches; the Clotho Spider’s tent and lentiform pockets.[3]
The Locust makes pits surmounted by a frothy chimney; the Mantis whips her glair into a frothy mass.[4] The Fly and the Butterfly, on the other hand, know nothing of these fond attentions: they limit themselves to laying their eggs at spots where the young can find board and lodging for themselves.[5] The Beetle also is generally extremely ignorant of the finer points of nest-building. By a very singular exception, the Dung-beetles, alone among the immense host of wearers of armoured wing-cases, have a special art of rearing, a system of upbringing which can bear comparison with that of the most gifted insects. How did they come by this industry? [[270]]
Venturesome minds, deluded by the greatly daring theorists, tell us that the science of the future, rich in evidence drawn from the mysteries of fibre and cell, will draw up an affiliation-table in which the animal kingdom will be classified so that the place occupied by a creature shall inform us of its instincts, without any need of preliminary observation. We shall determine the aptitudes by means of learned formulæ, even as numbers are determined by their logarithms. It is most impressive; but beware: we are dealing with Dung-beetles; let us consult them before we draw up the logarithmic table of instincts. The Onthophagus is related to the Copris, the Scarab and the Sisyphus, all of whom are versed in the art of making shapely pellets. Let us try to tell beforehand, according to the place which she occupies in the insect-table, going merely by the formula, what she is able to do in the way of nest-building.