Before leaving this repugnant milieu, one may still consider the leech. Hermaphrodite, they also practice reciprocal fecundation, but the position of their organs compels them to assume a peculiar position: the prong emerges from a pore near the mouth; the vagina is above the anus. The copulation of these wretched animals forms, therefore, a head-to-tail, the bocal sucker coinciding with the anal sucker.
Animals having both sexes, do not necessarily show sexual dimorphism. But neither this exact likeness of individuals, nor the double function with which they are charged, contradicts the general law which seems to wish that an individual should be due to elements coming from two different individuals. Autofecundation is exceptional, is very rare. Whether or no the individual possess the two genital glands, or one of them only, it needs a male, or an individual acting as male, and a female or an individual acting as female, to perpetuate life. Alternative hermaphrodism confirms these propositions, be it that the same gland transforms itself totally, turn by turn, into male principle, then into female principle; be it divided between a male half and a female half, these two halves ripen simultaneously or successively. When there is total or partial alternation, the male principle is ready first, and waits: thus the aggressivity of the male, and the passivity of the female are visible in the most obscure manifestations of sexual life: the fundamental psychology of an ascide does not differ from that of an insect, or from that of a mammal.
[CHAPTER XIII]
THE MECHANISM OF LOVE
V. Artificial fecundation.—Disjunction of the secreting apparatus from the copulating apparatus.—Spiders.—Discovery of their copulative method.—Brutality of the female.—Habits of the epeire.—The argyronete.—The tarantula.—Exceptions: the reapers.—Dragon-flies (libellule).—Dragon-flies (demoiselle) virgins and "jouvencelle."—Picture of their love affairs.
The apparatus for secreting sperm and that for copulating are sometimes separated. The female has a vagina normally situated; the male has no penis, or else it is situated in some part of the body not in symmetry with the receiving apparatus. It is then necessary either for the male to make an artificial penis, as one has seen in the cephalopodes, and as in the spider, or for him to engage in complicated manœuvres to dominate the female, and to engineer the conjunction of the two apparatus, as does the dragon-fly (libellule).
The method of most arachnids strangely resembles the medical practice called artificial fecundation, although it is hardly more so than normal fecundation. In both it is a question of putting spermatozoides in the way of encountering ovules: it matters little whether phallus or syringe be the vehicle. The spider uses a syringe. For a long time people thought that the whole genital apparatus was situated in the feelers of the male, but anatomy could find nothing there to resemble it. Savigny thought that the introduction of the feelers into the vulva was merely an excitative manœuvre, and that the true copulation followed. One had only observed half the act, the second phase. The first consists in the male's gathering up the semence in his own belly with the feelers; he then places it in the female organ. The maxillary peripalpe or antenna, thus transformed into a penis, contains a spiral canal which the male fills in placing it against the opening of his spermatic canals. One sees the joint of one of the knuckles open, letting appear a white bourrelet (pad with a hole in the middle), this is bent, and plunged into the vulva, it emerges and the insect flees. System marvellously adapted to the circumstances, for the female is ferocious and quite ready to devour her suitor. But is it the ferocity of the female which has modified the fecundating system, or is it the system, so lacking in tenderness, which has led the receptress to find only an enemy in the aspirant who advances horn to the fore? Acts which produce constant and useful results always seem to us ordered by an admirable logic; one need only give oneself up to a certain laziness of mind, to be led quite gently to call them providential and to fall little by little into the innocent nets of finalism.
Doubtless—and undeniable—there is a general finality, but one must conceive it as represented entire by the present state of nature. This will not be a conception of order, but a conception of fact, and in any case, the means used to attain this fact should in no way be integrated in the finality itself. None of the procedures of generation, for example, bears the mark of necessity. It is not the ferocity of the she-spider which demands the sexual habit; the female mantis is still more savage, and mantis' method is cavalage. It does not seem as if anything in nature were ordered in view of some benefit; causes blindly engender causes; some maintain life, others force it to progress, others destroy it; we qualify them differently, according to the dictates of our sensibility, but they are non-qualifiable; they are movements, and nothing else. The pebble ricochets on the water, or it doesn't; this has no importance in itself, nothing more will come of it and nothing less. It is an image of supreme finality: after eight or ten bounds, life, like the pebble thrown by a child, will fall into the abyss, and with it all the good and evil, all facts, all ideas, and all things.