The work, a graceful sphere about the size of a large cherry, is a masterpiece of stercoral architecture and may be compared with that which the Bull Onthophagus has already shown us. Little nodes, arranged in concentric lines and alternating like the tiles of a roof, adorn the object from pole to pole. Each of them must correspond with a stroke of the trowel putting its load of mortar in place. If you did not know what it was, you would take the thing for the chiselled kernel of some tropical fruit. A sort of rough pericarp completes the illusion. It is the rind of the pudding which surrounds the central jewel but is easily removed, just as the husk separates from the nut. When we have done the shelling, we are quite surprised to find this splendid kernel under its rustic wrapper. Such is the chamber built with a view to the metamorphosis. The larva spends the winter there in a state of torpor. I hoped to obtain the adult insect in the spring. To my great surprise, the larval stage continued until the end of July. It takes about a year, therefore, for the nymph to make its appearance. This slowness in maturing surprises me. Can it be the rule in the open fields? I think so, for in the confinement of my insect-house nothing happened, to my knowledge, that would occasion this delay. I therefore enter the result of my manœuvres without any fear of making a mistake: lying lifeless in its elegant and solid casket, the larva of the Bison Onitis takes twelve months to develop into a nymph, whereas those of the other Dung-beetles effect their transformation in a few weeks. As to stating or even suspecting the cause of this strange larval longevity, these are points which must be left in the limbo of the unexplained. Softened by the September rains, the stercoral shell, until now as hard as a plum-stone, yields to the hermit’s thrust; and the adult Beetle comes up into the light of day to lead a life of revelry so long as the mild atmosphere of the last days of summer permits. When the first cold weather sets in, he retires to his winter quarters underground and reappears in the spring to begin the cycle of life all over again. CHAPTER XVII THE BULL ONTHOPHAGUS: THE CELL Begun to-day and dropped to-morrow, taken up again later and again abandoned, according to the chances of the day, the study of instinct makes but halting progress. The changing seasons bring unwelcome delays, forcing the observer to wait till the following year or even longer for the answer to his eager questions. Moreover, the problem often crops up unexpectedly, as the result of some casual incident of slight interest in itself, and it comes in a form so vague that it gives little basis for precise investigation. How can one investigate what has not yet been suspected? We have no facts to go upon and are consequently unable to tackle the problem frankly.