on with all details strictly _en règle_. If the head of the _Scolia_ larva be taken out from the victim and applied to another part of the body of the _Cetonia_, the result is that it cannot eat; even if it be replaced in the original situation, after being taken away, it frequently happens that the _Cetonia_ larva dies, its death involving also that of the destroyer. It is necessary, too, that the victim should be paralysed, for if an intact _Cetonia_ larva be taken and bound down in such a position that it cannot move, and if a small orifice in its skin be made in the proper spot and a young _Scolia_ larva be placed on it, the little parasite will avail itself of the opportunity and commence to feed on the larva provided for it, but the latter will speedily die, and the _Scolia_ necessarily perishes with it. Thus both the paralysis of the victim and the special mode of eating are essential to the life of the _Scolia_. The operation of stinging the larva so as to produce the necessary paralysis, or rather insensibility, is a difficult one, and requires great skill and patience. The _Cetonia_ larva is of large size, and must be pierced in one particular spot; {99}in order to reach this the _Scolia_ mounts on its victim, and is frequently dislodged by its struggles; sooner or later, however, the proper position is obtained by the wasp, and the larva is then stung in the exact spot necessary to allow the sting (and the poison introduced by it) to reach the most important of the nervous ganglia that control the movements of the body, this spot being, in the case of the _Cetonia_, the line of demarcation between the pro- and meso-thorax, on the middle line of the ventral surface of the body. The _Scolia_ gives but one sting to the victim, and this it will not administer until it can do so exactly in the proper place. This practice of devouring the victim slowly, without killing it till all is eaten, is very widely spread in the Hymenoptera, and it is satisfactory to find that we may infer from Fabre's observations that it is not so horrible as it would at first appear; for it is probable that the stinging prevents decomposition of the victim, not by reason, as some have supposed, of the poison injected by the wasp having an antiseptic effect, but rather by means of destroying sensibility, so that the creature does not die from the pain, as it is believed it did in certain cases where Fabre induced the young _Scolia_ larva to feed on a victim that had not been stung. We may here remark that very little exact information exists as to the operation of stinging. Fabre attaches great importance to the sting being inflicted on a nerve-ganglion. Whether a sting that did not reach this part might not have a sufficient effect appears, however, doubtful.[46]