This fractional division is a judicious method. Because of the enormous amount of friction in the narrow and uneven natural shaft, the Beetle would never succeed in hoisting the great cylinders of his mound in one lump; he carries them up in loads which are not beyond his powers and which are afterwards joined and welded together. I am inclined to believe that this work of assembling the component parts is performed in the slightly sloping vestibule which usually precedes the perpendicular shaft. Here no doubt the successive clods are compressed into one very heavy cylinder, which is yet easily moved along an almost horizontal road. Then the Minotaur, with a last thrust of his trident, pushes out the lump, which joins the others on the sides of the mound. They are like so many blocks of hewn stone forbidding access to the home. The rubbish thus suitably moulded provides a Cyclopean system of fortification. In the glass tube, the climbing is such difficult work that the insect is soon discouraged. The frail footholds left by the load crumble and fall off, swept away by the tarsi vainly seeking a support; and the tube again becomes smooth over wide extents of its surface. The climber ends by giving up struggling against the impossible; he abandons his bundle and drops to the bottom. The works cease henceforth; the couple have recognized the treachery of their strange dwelling. Both of them try to get away. Their uneasiness is betrayed by continual attempts to escape. I set them free. They have told me all that they were able to tell me in conditions so favourable to me and so bad for themselves. To return to the large apparatus, where the work is proceeding correctly. The boring, begun in March, finishes by the middle of April. From this time onward, my daily visits no longer show me on the top of the mound a plug of fresh earth, marking a recent ejection of rubbish. It must therefore take two or three weeks at least to excavate the dwelling. My observations in the open even lead me to think that a month or longer is not excessive. My two captives, disturbed in the midst of their earlier labours and pressed for time by the lateness of the season, cut short this work, which for that matter they were unable to continue when the cork stopper appeared at the bottom of the tube as an insuperable obstacle. The others, working in freedom, have an unlimited depth of sand at their disposal. They have plenty of leisure, if they start work in good time. Even before the end of February we see plenty of mounds. Later, these will mark the sites of shafts four or five feet deep. Such pits as these require a full month’s labour, if not more.