Yes, my revered master, I will admit without hesitation that the bramble-dwellers leave their sheath in the converse order to that of their ages: the youngest first, the oldest last; if not invariably, at least very often. But does the hatching, by which I mean the emergence from the cocoon, take place in the same order? Does the evolution of the elder wait upon that of the younger, so that each may give those who would bar his passage time to effect their deliverance and to leave the road clear? I very much fear that logic has carried your deductions beyond the bounds of reality. Rationally speaking, my dear sir, nothing could be more accurate than your inferences; and yet we must forgo the theory of the strange inversion which you suggest. None of the Bramble-bees with whom I have experimented behaves after that fashion. I know nothing personal about Odynerus rubicola, who appears to be a stranger in my district; but, as the method of leaving must be almost the same when the habitation is exactly similar, it is enough, I think, to experiment with some of the bramble-dwellers in order to learn the history of the rest. My studies will, by preference, bear upon the Three-pronged Osmia, who lends herself more readily to laboratory experiments, both because she is stronger and because the same stalk will contain a goodly number of her cells. The first fact to be ascertained is the order of hatching. I take a glass tube, closed at one end, open at the other and of a diameter similar to that of the Osmia's tunnel. In this I place, one above the other, exactly in their natural order, the ten cocoons, or thereabouts, which I extract from a stump of bramble. The operation is performed in winter. The larvae, at that time, have long been enveloped in their silken case. To separate the cocoons from one another, I employ artificial partitions consisting of little round disks of sorghum, or Indian millet, about half a centimetre thick. (About one-fifth of an inch.--Translator's Note.) This is a white pith, divested of its fibrous wrapper and easy for the Osmia's mandibles to attack. My diaphragms are much thicker than the natural partitions; this is an advantage, as we shall see. In any case, I could not well use thinner ones, for these disks must be able to withstand the pressure of the rammer which places them in position in the tube. On the other hand, the experiment showed me that the Osmia makes short work of the material when it is a case of drilling a hole through it.