Ten hours after the operation, I examine the grubs again. The hind-legs are tremulous and are no longer of use for locomotion. Paralysis is overtaking them. Next day, they are inert; so are the middle legs. The head and the fore-legs are still working. On the day after, the whole grub is motionless, except the head. Lastly, on the fourth day, the creature is dead, really dead, for it shrivels, dries up and goes black, while the larvæ subjected to the thoracic operation with a view to being used for provisions remain full and fresh-coloured for weeks and months. Did the grub die of its stings in the abdomen? No, for the others, stung in the thorax, do not die. It is the Odynerus’ cruel tooth and not the sting that killed it. With the tip of the abdomen crushed under the mandibles and the intestinal capsule pulled out by the roots, life has ceased to be possible. CHAPTER IX INSECT GEOMETRY The industry of insects, especially that of the Bees and Wasps, abounds in tiny marvels. Newly manufactured with the cotton supplied by various fluff-covered plants, the nest of certain Anthidia forms an exquisitely graceful pouch. It is accurately fashioned, white as snow, pleasing to the eye and softer to the touch than Swan’s-down. The Humming-bird’s nest, a bowl hardly half the size of an apricot, is by comparison a piece of clumsy felt. But this perfection is of brief duration. The artist is hampered by the exigencies of the space at her disposal. Her workshop is a chance shelter, a tunnel incapable of modification, which she has to use as she finds it. In this narrow retreat, therefore, the cotton purses are placed in a row, each compressing the others and distorting their form; they are welded at either end to their neighbours, till the whole becomes a lumpy pillar moulded to the volume of the container. For lack of space, the weaver has been unable to continue her textile fabric in accordance with the exquisite design dictated by her instinct. A length of rope, of indifferent merit, takes the place of the superb masterpiece of felt which the Anthidium would have created had she been working at isolated cells. The Chalicodoma of the Walls, when building on a pebble, first raises a turret of faultless geometrical proportions. The dust scraped from the hardest spots in the highways and kneaded with saliva provides the mortar. To make a more solid job of things and also to economize cement, which takes a long time to collect and prepare, tiny bits of gravel are encrusted in the outer surface before the material sets. In this way the initial building becomes a rustic rockwork fortress, which is quite pretty to look at.