But it must be kept upright and completed with different accessories essential to successful operation. For this purpose, three bamboo canes are planted in the earth contained in a large flower-pot. Joined at their tips, they form a tripod, a frame supporting the whole structure. The tube is set up in the centre of the triangular base. A small earthenware pie-dish with a hole made in the bottom, receives the open upper end, which projects a little and holds a layer of earth that comes level with the brim. This will represent, around the mouth of the shaft, the space in which the insect can attend to its business, either to shoot the rubbish from the shaft or to gather the provisions round about. Lastly, a glass bell, fitting into the dish, prevents escape and preserves the slight quantity of moisture needed. A few supporting strings and bits of wire keep the whole thing firmly fixed. We must not overlook one most important detail. The diameter of the tube is about twice that of the natural burrow. Therefore, if the insect digs along the axis and in an exactly perpendicular direction, it will have at its disposal more than the required width. It will obtain a channel lined on every side by a wall of sand a few millimetres thick. We may however assume that the digger, knowing nothing of geometrical precision and ignorant of the conditions provided for it, will take no account of the axis and will deviate from it to one side or the other. Moreover, the least additional resistance in the substance traversed will cause the Beetle to turn aside slightly, now hither, now thither. Consequently the glass wall will be completely denuded at sundry points; windows will be formed, chinks upon which I rely to make observation possible, but which will be hateful to the darkness-loving workers. To make sure of these windows and save the insect from them, I sheath the tube in a few cardboard sheaths which can be gently slipped up and down and which fit inside one another. With this arrangement, I shall be able, when required, and without distracting the insect from its work, to create alternately, by a simple movement of the thumb, a little light for myself and darkness for the Beetle. The distribution of the movable sheaths, which slip up or down as needed, will allow the tube to be examined from end to end as and when the accidents of boring open up new windows.