Oh, my poor joints, grown rusty with age! To suspect the existence of a beautiful problem underground and to be unable to dig! The zeal survives, as ardent as in the days when I used to demolish the spongy slopes beloved of the Anthophoræ; [37] the love of research has not abated; but my strength fails me. Fortunately I have an assistant in the person of my son Paul, who lends me the vigour of his wrists and the suppleness of his back. I am the head, he is the arm. The rest of the family, including the mother—and she not the least eager—usually go with us. You cannot employ too many eyes when the pit becomes deep and you have to observe from a distance the tiny objects unearthed by the spade. What one overlooks another will detect. Huber, [38] when he was blind, studied the Bees through the intermediary of a clear-sighted and devoted helper. I am even better off than the great Swiss naturalist. My sight, which is still fairly good though much worn, is assisted by the perspicacious eyes of all my family. I owe it to them that I am able to continue my research-work: let me thank them here and now. We are on the spot early in the morning. We find a burrow with a large mound formed of cylindrical plugs forced out as though by blows of the hammer. We clear away this hillock and a pit opens below it. A good, long reed, gathered on the way, is inserted in the hole. Pushed farther home, as the surface soil is cleared away, it will serve us as a guide. The soil is quite loose, unmixed with pebbles, which are obnoxious to the digging insect that loves the perpendicular and especially obnoxious to the cutting edge of the exploring spade. It consists solely of sand cemented with a little clay. The digging would therefore be easy, if one had not to reach depths in which tools become extremely difficult to handle unless the whole area is overturned. The following method gives good results without unduly increasing the volume of earth removed, a procedure to which the owner might object. A space of roughly a yard in radius is attacked around the shaft. As the guiding reed is laid bare, we push it lower in. It began by going about nine inches underground, it is now eighteen inches down. Soon it becomes impracticable to remove the earth with the spade, which is hampered by lack of room. We have to go on our knees, collect the rubbish in both hands and toss it outside. The more we do so, the deeper the hole becomes, increasing the already enormous difficulty. A moment arrives when, to continue, we are obliged to lie flat on our stomachs and dip the front of our bodies into the hole, as far as our more or less supple waists allow. Each dip flings up a good handful of earth. And the reed goes lower and lower, without giving any indication of an immediate check.