covering them with a thick coat to ensure their protection against heat and cold. This coat she purifies from time to time by the lachrymal humours, and she has made the surface lubricous and slippery, to protect the eye against the effects of a sudden shock. CHAP. 55.—THE NATURE OF THE PUPIL—EYES WHICH DO NOT SHUT. In the midst of the cornea of the eye Nature has formed a window in the pupil, the small dimensions of which do not permit the sight to wander at hazard and with uncertainty, but direct it as straight as though it were through a tube, and at the same time ensure its avoidance of all shocks communicated by foreign bodies. The pupils are surrounded by a black circle in some persons, while it is of a yellowish cast with others, and azure again with others. By this happy combination the light is received by the eye upon the white that lies around the pupil, and its reflection being thus tempered, it fails to impede or confuse the sight by its harshness. So complete a mirror, too, does the eye form, that the pupil, small as it is, is able to reflect the entire image of a man. This[200] is the reason why most birds, when held in the hand of a person, will more particularly peck at his eyes; for seeing their own likeness reflected in the pupils, they are attracted to it by what seem to be the objects of their natural affection. It is only some few beasts of burden that are subject to maladies of the eyes towards the increase of the moon: but it is man alone that is rescued from blindness by the discharge of the humours[201] that have caused it. Many persons have had their sight restored after being blind for twenty years; while others, again, have been denied this blessing from their very birth, without there being any blemish in the eyes. Many persons, again, have suddenly lost their sight from no apparent cause, and without any preceding injury. The most learned authors say that there are veins which communicate from the eye to the brain, but I am inclined to think that the communication is with the stomach; for it is quite certain that a person never loses the eye without feeling sickness at the stomach. It is an important and sacred duty, of high sanction among the Romans, to close[202] the eyes of the dead, and then again to open them when the body is laid on the funeral pile, the usage having taken its rise in the notion of its being improper that the eyes of the dead should be beheld by man, while it is an equally great offence to hide them from the view of heaven. Man is the only living creature the eyes of which are subject to deformities, from which, in fact, arose the family names of “Strabo”[203] and “Pætus.”[204] The ancients used to call a man who was born with only one eye, “cocles,” and “ocella,” a person whose eyes were remarkably small. “Luscinus” was the surname given to one who happened to have lost one eye by an accident.