One need not wait for a minute description of the exterior love mechanism of all animal species. It would be long, difficult and boresome. A few characteristic examples will be enough. The duration of the coition is extremely variable, even in superior mammals. Very slow for dogs, coupling is but a thunderclap for the bull, the ram's is called the "lutte" (strife). The bull merely enters and leaves, and it is a spectacle for philosophers, for one understands immediately that what drives the fiery beast at his female is not the lure of a pleasure too swift to be deeply felt, but a force exterior to the individual although included in his organism. By its long grievous duration the coition of dogs leads to analogous reflections In triviis quum sæpe canes discedere aventes Diversi cupidine summis ex viribus tendunt. --LUCRETIUS. This is because the dog's penis contains a hollow bone giving passage to the urethra. Around this bone are gathered the erectile tissues whereof one, the node of the prong, swells disproportionately during coition and prevents the separation of the two animals after the act is accomplished. They remain a long time uncomfortable, not managing to free themselves until long after their desire has turned to disgust, grotesque and lamentable symbol of many a human liaison. Our other familiar animal, the cat, is not more happy in his affections. His penis is indeed furnished with thorns, with homy papilla toward the tip, and the intromission as well as the separation is only accomplished with groans. What one hears at night are not cries of voluptuousness but of suffering, the bowlings of a beast whom nature has caught in the trap. This does not prevent the female from being very enterprising; responding to the cries of the pursuing male she excites him in a hundred ways, biting at neck and belly with an insistence which has, they say, provided a metaphor in the erotic vocabulary. Biting the neck is much more curious, as it is of a much less direct intention. Bitches also bite the neck of the dog in prelude. For near the neck is situated the bulb, original knot of nerves governing the secret parts and the genital region. The pain which accompanies sexual acts ought to be differentiated, with precision, from passive suffering. It is very possible (women can testify to the fact) that sighs and even cries emitted at such time are the expression of a mixed sensation, wherein joy has almost as great a part as suffering. We must not judge feline exclamations from the shrillness of timbre; tortured by the male prong the she-cats howl, but they await the supreme benediction. The rigour of the first approaches is perhaps but the promise of deeper delights: at any rate some women have thought so.