(For these Sand-wasps, cf. "The Hunting Wasps": chapters 13 and 18 to 20.--Translator's Note.)My readers may differ in appraising the comparative value of the trifling discoveries which entomology owes to my labours. The geologist, the recorder of forms, will prefer the hypermetamorphosis of the Oil-beetles (The chapter treating of this subject has not yet been translated into English and will appear in a later volume.--Translator's Note.), the development of the Anthrax (Cf. "The Life of the Fly": chapter 2.--Translator's Note.) or larval dimorphism; the embryogenist, searching into the mysteries of the egg, will have some esteem for my enquiries into the egg-laying habits of the Osmia (Cf. "Bramble-bees and Others": chapter 4.--Translator's Note.) ; the philosopher, racking his brain over the nature of instinct, will award the palm to the operations of the Hunting Wasps. Iagree with the philosopher. Without hesitation, I would abandon all the rest of my entomological baggage for this discovery, which happens to be the earliest in date and that of which I have the fondest memories. Nowhere do I find a more brilliant, more lucid, more eloquent proof of the intuitive wisdom of instinct; nowhere does the theory of evolution suffer a more obstinate check.
Darwin, a true judge, made no mistake about it. (Charles Robert Darwin, born the 12th of February, 1809, at Shrewsbury, died at Down, in Kent, on the 19th of April, 1882. For an account of certain experiments which the author conducted on his behalf, cf. "The Mason-bees": chapter 4.--Translator's Note.) He greatly dreaded the problem of the instincts. My first results in particular left him very anxious. If he had known the tactics of the Hairy Ammophila, the Mantis-hunting Tachytes, the Bee-eating Philanthus, the Calicurgi and other marauders, his anxiety, I believe, would have ended in a frank admission that he was unable to squeeze instinct into the mould of his formula. Alas, the philosopher of Down quitted this world when the discussion, with experiments to support it, had barely begun: a method superior to any argument! The little that I had published at that time left him with still some hope of an explanation. In his eyes, instinct was always an acquired habit. The predatory Wasps killed their prey at first by stabbing it at random, here and there, in the softest parts. By degrees they found the spot where the sting was most effectual; and the habit once formed became a true instinct. Transitions from one method of operation to the other, intermediary changes, sufficed to bolster up these sweeping assertions. In a letter of the 16th of April, 1881, he asks G.J. Romanes to consider the problem:
"I do not know," he says "whether you will discuss in your book on the mind of animals any of the more complex and wonderful instincts. It is unsatisfactory work, as there can be no fossilised instincts, and the sole guide is their state in other members of the same order, and mere PROBABILITY.
"But if you do discuss any (and it will perhaps be expected of you), Ishould think that you could not select a better case than that of the sand-wasps which paralyse their prey as described by Fabre in his wonderful paper in the "Anales des sciences naturelles," and since amplified in his admirable "Souvenirs..."I thank you, O illustrious master, for your eulogistic expressions, proving the keen interest which you took in my studies of instinct, no ungrateful task--far from it--when we tackle it as it should be tackled: from the front, with the aid of facts, and not from the flank, with the aid of arguments. Arguments are here out of place, if we wish to maintain our position in the light. Besides, where would they lead us? To evoking the instincts of bygone ages, which have not been preserved by fossilization?
Any such appeal to the dim and distant past is quite unnecessary, if we wish for variations of instinct, leading by degrees, according to you, from one instinct to another; the present world offers us plenty.
Each operator has her particular method, her particular kind of game, her particular points of attack and tricks of fence; but in the midst of this variety of talents we observe, immutable and predominant, the perfect accordance of the surgery with the victim's organization and the larva's needs. The art of one will not explain the art of another, no less exact in the delicacy of its rules. Each operator has her own tactics, which tolerate no apprenticeship. The Ammophila, the Scolia, the Philanthus and the others all tell us the same thing: none can leave descendants if she be not from the outset the skilful paralyser or slayer that she is to-day. The "almost" is impracticable when the future of the race is at stake. What would have become of the first-born mammal but for its perfect instinct of suckling?
And then, to suppose the impossible: a Wasp discovers by chance the operative method which will be the saving attribute of her race. How are we to admit that this fortuitous act, to which the mother has vouchsafed no more attention than to her other less fortunate attempts, could leave a profound trace behind it and be faithfully transmitted by heredity? Is it not going beyond reason, going beyond the little that is known to us as certain, if we grant to atavism this strange power, of which our present world knows no instance? There is a good deal to be said for this point of view, my revered master! But, once more, arguments are here out of place;there is room only for facts, of which I will resume the recital.
