Note 5 — Chapter iii · A SCIENTIFIC SLAUGHTERER

The operating method is of the simplest. It is a question of taking a needle, or, better and more convenient, the point of a fine steel nib, and introducing a tiny drop of some corrosive fluid into the thoracic motor centres, by pricking the insect slightly at the junction of the prothorax, behind the first pair of feet. The fluid which I employ is ammonia; but obviously any other liquid as powerful in its action would produce the same results. The nib being charged with ammonia as it might be with a very small drop of ink, I give the prick. The effects obtained differ enormously, according to whether we experiment upon species whose thoracic ganglia are close together or upon species in which those same ganglia are far apart. In the first class, my experiments were made on Dung-beetles: the Sacred Scarab5 and the Wide-necked Scarab; on Buprestes: the Bronze Buprestis; lastly, on Weevils, in particular on the Cleonus hunted by the heroine of this essay. In the second class, I experimented on Ground-beetles: Carabi, Procrustes, Chlænii, Sphodri, Nebriæ; on Longicornes: Saperdæ and Lamiæ; on Melasoma-beetles: Cellar-beetles, Scauri, Asidæ.