CHAPTER XXVI
Scorpions and suicide—The act proved—Intention probable—Conflicting evidence—Scorpions and cockroaches—Concentrating backwards—Economy of poison—Decorous feeding.
THE assertion that scorpions are occasionally luminous—if indeed it has ever been seriously made—does not appear to have received confirmation. Of fire, indeed, these creatures have a horror, but that probably relates to its property—heat—to which they are extremely sensitive. The popular belief is, that, if surrounded by fire, a scorpion will deliberately sting itself to death. Of the fact, or, at least, of the fact of the self-inflicted sting, there can be little doubt, but in regard to the motive there is room for difference of opinion. Mr. Pocock says, truly enough, that it is à priori improbable that the scorpion has any intention of killing itself.[[154]] But what, then, is its intention in stinging itself, supposing that it deliberately does so? Nor must it be forgotten that the idea of death—of destruction—must be indissolubly associated in the scorpion’s mind with the use of its sting, since it uses it with that purpose only, and that is the result which constantly attends its use. Is it, then, really so improbable that it stings itself with the same intention as that with which it stings other creatures?—or, rather, with what other possible intention can it do so, assuming the act to be a voluntary one?
Nor would it be necessary to prove the intention that the sting, thus delivered, should be fatal in its effects, and, in regard to this, Mr. Bourne has satisfied himself by experiments with some Indian scorpions that a self-inflicted wound, or even wounds inflicted by individuals of the same species on one another, have no effect. On the other hand, he found that a moderately high temperature was fatal to his scorpions, and so concludes that this has been the real cause of death in all such cases as we are here considering.[[154]]
The above theory, however, hardly accords with the experience of Mr. W. G. Bidie, also of India, and that very part of it where Mr. Bourne’s experiments were made—viz. Madras. Writing to Nature, he says: “One morning a servant brought me a large specimen of this scorpion (the common black one of Southern India), which, having stayed out too long in its nocturnal rambles, had apparently got bewildered at daybreak and been unable to find its way home. To keep it safe the creature was at once put into a glazed entomological case. Having a few leisure minutes in the course of the forenoon, I thought I would see how my prisoner was getting on, and to have a better view of it, the case was placed in a window in the rays of the hot sun. The light and heat seemed to irritate it very much, and this recalled to my mind a story which I had read somewhere that a scorpion on being surrounded with fire had committed suicide. I hesitated about subjecting my pet to such a terrible ordeal, but taking a common botanical lens, I focussed the rays of the sun on its back” (so that Apollo may have flayed Marsyas as a mild alternative). “The moment this was done it began to run hurriedly about the case, hissing and spitting in a very fierce way. This experiment was repeated some four or five times with like results, but on trying it once again the scorpion turned up its tail and plunged the sting, quick as lightning, into its own back. The infliction of the wound was followed by a sudden escape of fluid, and a friend, standing by me, called out, ‘See! it has stung itself: it is dead.’ And sure enough in less than half a minute life was quite extinct.”
This seems plain enough. The scorpion had not died of the heat, up to the moment at which it stung itself—an act which would require some vital energy. It did sting itself, and in less than half a minute afterwards it was dead. Moreover, as the experiments with the lens were intermittent, there seems no more reason why the last one should have been fatal than the other four or five. It is, perhaps, possible to imagine that the scorpion was almost dead before, that the last heating caused it to expire, and that in the moment of doing so it stung itself by involuntary muscular action. There is nothing, however, in the narrative to suggest this, but quite the contrary.
Supposing the sting to have been a voluntary act, what could the scorpion have intended except to injure itself? Had it ever in its life used its sting with any other purpose than that of doing injury? Mr. Bidie adds: “I have written this brief note to show (1) that animals may commit suicide; (2) that the poison of certain animals may be destructive to themselves.”[[155]]
Writing several years later, also to Nature, Dr. Allen Thomson, F.R.S., gives the following account, not, indeed, of his own experience, but that of an eye-witness in whom he feels full confidence. He says: “While residing, many years ago, during the summer months, at the baths of Sulla, in Italy, in a somewhat damp locality, my informant, together with the rest of the family, was much annoyed by the frequent intrusion of small black scorpions into the house, and their being secreted among the bedclothes, in shoes, and other articles of dress. It thus became necessary to be constantly on the watch for these troublesome creatures, and to take means for their removal and destruction. Having been informed by the natives of the place that the scorpion would destroy itself if exposed to a sudden light, my informant and her friends soon became adepts in catching the scorpions and disposing of them in the manner suggested. This consisted in confining the animal under an inverted drinking-glass or tumbler, below which a card was inserted, and then, waiting till dark, suddenly bringing the light of a candle near to the glass in which the animal was confined. No sooner was this done than the scorpion invariably showed signs of great excitement, running round and round the interior of the tumbler with reckless velocity for a number of times. This state having lasted for a minute or more, the animal suddenly became quiet, and, turning its tail on the hinder part of its body over its back, brought its recurved sting down upon the middle of the head, and, piercing it forcibly, in a few seconds became quite motionless, and, in fact, quite dead. This observation was repeated very frequently.”[[156]]