This difficulty removed, a far graver one presents itself. Armed with his scalpel, the anatomist can direct its point where he will in spite of obstacles which he may have to set aside. The Hymenopteron has no choice. Its victim is a solidly cuirassed beetle, its lancet a dart, extremely delicate, which the horny mail would certainly turn aside. Only certain points are vulnerable to the frail tool, namely, the joints, protected simply by a membrane with no power of resistance. But the joints of the limbs, although vulnerable, do not in the least fulfil the necessary conditions, for through these the utmost that could be obtained is local paralysis, not one affecting the whole organism of motion. Without any prolonged struggle, without repeated operations, which, if too numerous, might endanger the victim’s life, the Hymenopteron has, if possible, to abolish all motive power at one blow. Therefore she must direct her dart at the nervous centres, the source of the power of motion whence radiate the nerves running up to the various organs of movement. Now these sources of locomotion, these nervous centres, consist of a certain number of ganglia, more numerous in the larva, less so in the perfect insect, and arranged on the median line of the under surface in a string of beads more or less distant and connected by a double ribbon of nervous tissue. In all insects which have reached the perfect state the ganglia called thoracic, i.e. those furnishing nerves to wings and feet and governing their movements, are three in number. Here are the points to be struck: if their action can be in any way destroyed, the possibility of movement is destroyed also. Two ways of reaching these motive centres offer themselves to the feeble dart of the Hymenopteron; one, the joint between neck and corslet; the other the spot where the latter joins the continuation of the thorax, between the first and second pair of feet. The way through the neck does not answer; it is too far from the ganglia, which lie near the base of the feet which they animate. The blow must be dealt at the other spot, and through that only. Thus would an academy decide where Claude Bernards illuminated the question by their profound science. And it is precisely there, between the first and second pairs of feet on the median line of the under surface, that the Cerceris plunges her lancet. By what learned intelligence must she be inspired!