The idea of finality leads one back to the idea of fact, one is no longer tempted to attempt an explanation of nature. One would try modestly to reconstruct the chain of causes and, as a great number of rings will always be lacking, and as the absence of one ring alone would suffice to unhook the whole reasoning, one will do this in a piety tempered by scepticism. The epirus, although a spider, is not an ill-conditioned beast; she is episcopal, she carries on her back a pretty white cross upside down. The large ones are the females; the very small ones, the males. Both hook their webs upon bushes, on shrubs, live without knowing each other until instinct has spoken. A day comes when the male is restless; the gnats fail to satisfy him; he leaves, he abandons the home he will perhaps not see again. He is not, indeed, without misgivings, and fear is mingled with his desire, for the mistress he seeks is an ogress. Thus he prepares a way of retreat in case of combat; he stretches a thread from the female's web to a neighbouring branch, road of entry, gate of exit. Often, the instant he shows himself with his excited air, the female epirus leaps on him and eats him without formality. Is it ferocity? No, stupidity. She also is awaiting the male, but her attention is distraught between the coming of the caller and the coming of prey. The web has shaken, she leaps, enlaces, devours. Perhaps a second male if he attempt the pass, will be gladly received, the first sacrifice accomplished, perhaps this mistake, if it is one, will wake all the amorous attention of the distracted female? Ferocity, stupidity; there is another explanation which I will give later, apropos the mantis and the green grass-hopper: it is very probable that the sacrifice of the male, or of a male, is absolutely necessary, and that it is a sexual rite. The little male approaches; if he is recognized, and if his coming coincides with the genital state of the female, she merely behaves like all the rest of her peers, and even though she be the larger and stronger, she flees; she lets herself, full of coquetry, slide down a thread; the male imitates the play, he descends, she mounts, he mounts, the acquaintance is made, they feel each other, they pat each other, the male fills his pump, the mating is accomplished. She is rapid, the male stays on guard, ready to flee at the least movement of his adversary; often he hasn't time. Scarcely has the fecundation been finished when the ogress turns, leaping, and devours the suitor on the very spot of his amours. They say that she does not always wait for the end of the operation, and that preferring a good meal to a caress, she interrupts the performance with a slap of her mandibles. When the male has the luck to escape he disappears like a flash, goes down his thread like greased lightning. The argyronete uses manœuvres analogous, but even more curious. It is a water spider, which goes under water in an ingenious small diving-bell, a future