The most immediate physical cause of their inclination to seize other animals by surprise, comes from the advantage they receive from the particular conformation of their eyes. The pupil in man, and many other animals, is capable of a certain degree of contraction and dilatation; it enlarges a little when the light is faint, and contracts when it becomes too strong; in cats and nocturnal birds, as owls, &c. this contraction and dilatation is so considerable that the pupil, which in the dark is large and round, becomes in the day, long and narrow like a line; and therefore these animals see better in the night than in the day. There is a perpetual contraction in the eye of the cat during the day, and it is only by a great effort that he can see in a strong light, whereas, in the twilight, the pupil resumes its natural form, he sees perfectly, and profits from this superiority to know, attack, and surprise his prey. It cannot be said that cats, though living in our houses, are entirely domestic. The most familiar are not under any subjection, but rather enjoy perfect freedom, as they only do just what they please, and nothing is capable of retaining them in a place which they are inclined to desert. Besides, most of them are half wild, know not their masters, frequent other granaries, and never visit the kitchens and offices belonging to the house but when pressed to it by hunger. Cats have less attachment to persons than to houses. When taken to the distance of a league or two they will return to their former abode of their own accord, possibly because they there know all the retreats of the mice, the outlets and passages about the house, and because the labour of the journey back is less than it would be to acquire the same facility in a new place. They fear water, cold, and bad smells; they love to be in the sun, and to lie in warm places; they are very fond of perfumes, and willingly allow themselves to be taken and caressed by those who make use of them. The scent of the valerian root has so powerful an effect on them that it appears to transport them with pleasure; to preserve this plant in the gardens it is necessary to surround it with a close fence, for the cats smell it at a distance, will come about it in numbers, and by rubbing and passing and repassing over it very soon destroy the plant. They do not come to their full growth in less than fifteen or eighteen months, but they are capable of engendering before the end of the first year, and they can procreate all their lives, which seldom exceeds eight or nine years; they are notwithstanding, very lively and hardy, and more nervous than most other animals which live longer.