This obelisk is hollow along its axis. We have seen it serving as a lift for the rubbish which the young grub throws out when deepening its natal basin and converting it into a passage which gives access to the kernel. But this is a very secondary function; it has another of greater importance. Every egg breathes. In its cup with the sawdust mattress, the Weevil’s egg needs a supply of air, a very moderate supply, no doubt, but it must have some. Through the passage in its conical roof the air reaches it and is renewed, even if bad luck has filled the crater with gum. Every living creature breathes. The maggot has entered the stone of the fruit by making an opening such as our finest drills could not equal for precision. It is now in a sealed casket, an air-tight barrel, tarred, moreover, with gummy pulp. Yet it must have air, even more than the egg. Well, ventilation is effected by the shaft which the grub has driven through the thickness of the stone. However tiny the air-hole, it is big enough provided it be not clogged. There is no need to fear anything of the sort, even with an excess of gum. Above the ventilator rises the defensive cone, continuing, by means of its tunnel, the communication with the outer world. I wanted to know how anchorites more vigorous than the hermit of the sloe would behave in an exceedingly limited and renewable atmosphere. I must have them in the period of repose which precedes the metamorphosis. The insect has then completed its growth; it is no longer feeding; it is almost inert. It is living as cheaply as it can and may be compared with a germinating seed. Its need of air is reduced to the lowest possible limit. Indifferent as to choice, I use what I have within reach and first of all the larvæ of the Brachycerus, the Weevil that feeds on garlic. A week ago they abandoned their cloves and went down into the earth, where, motionless in their hollows, they are making ready for the transformation. I place six of them in a glass tube, sealed at one end by the blow-pipe. I divide them one from the other by means of cork partitions, so as to allow each a cell comparable in capacity with the natural lodging. Thus stocked, the tube receives a first-rate cork covered with a layer of sealing-wax. It is absolutely closed. No gaseous exchanges are possible between the inside and the outside; and each larva is strictly limited to the small quantity of atmosphere which I have meted out to it approximately, according to the capacity of the underground cells. Similar tubes are prepared, some with Cetonia-grubs taken from the shells in which they were awaiting metamorphosis and others with nymphs of the same species. What will become of these various prisoners, whose life is latent, suspended, demanding a minimum of ventilation?