With a slant towards the thorax, the sting wounds the little mass of nerve-cells in the thorax. This is the regulation stroke, the one which will induce paralysis and leave the small amount of life needed to keep the provisions fresh. A millimetre higher kills; a millimetre lower paralyses. On this tiny deviation the salvation of the Scolia race depends. You need not fear that the operator will make any mistake in this micrometrical performance: her sting always slants towards the thorax, although the opposite inclination is just as practicable and easy. What would be the outcome of a there or thereabouts under these conditions? Very often a corpse, a form of food fatal to the grub. The Two-banded Scolia stings a little lower down, on the line of demarcation between the first two thoracic segments. Her position is likewise transversal in relation to the Cetonia-grub; but the distance of the cervical ganglia from the point where the sting enters would possibly not allow the weapon turned towards the head to inflict a lesion followed by sudden death as in the above instance. I am calling this witness with another object. It is extremely unusual for the operator, no matter what her prey or her method, to make a slight mistake and sting merely somewhere near the requisite point. I see them all groping with the tip of the abdomen, sometimes seeking persistently, before unsheathing. They thrust only when the point beneath the sting is precisely that at which the wound will produce its full effect. The Two-banded Scolia in particular will struggle with the Cetonia-grub for half an hour at a time to enable herself to drive in the stiletto at the right spot. Wearied by an endless scuffle, one of my captives committed before my eyes a slight blunder, an unprecedented thing. Her weapon entered a little to one side, not quite a millimetre from the central point and still, of course, on the line of demarcation between the first two thoracic segments. I at once laid hold of the precious specimen, which was to teach me curious matters about the effects of an ill-delivered stroke. If I myself had made the insect sting at this or that point, there would have been no particular interest in it: the Scolia, held between the finger-tips, would wound at random, like a Bee defending herself; her undirected sting would inject the poison at haphazard. But here everything happened by rule, except for the little error of position.