quorum duri sunt minus cernunt quam quorum umidi. serpentium catulis et hirundinum pullis si quis eruat 153renasci tradunt. insectorum omnium et testacei operimenti oculi moventur sicut quadripedum aures. quibus fragilia operimenta, his oculi duri. omnia talia et pisces et insecta non habent genas nec integunt oculos; omnibus membrana vitri modo tralucida obtenditur.154
LVI. Palpebrae in genis homini utrimque. mulieribus fuco1 etiam infectae cotidiano: tanta est decoris adfectatio ut tinguantur oculi quoque. alia de causa hoc natura dederat, ceu vallum quoddam visus et prominens munimentum contra occursantia animalia aut alia fortuito incidentia. defluere eas 155haut inmerito venere abundantibus tradunt. ex ceteris nulli sunt nisi quibus et in reliquo corpore pili. sed quadripedibus in superiore tantum gena, volucribus in inferiore, et quibus molle tergus, ut serpentibus, et quadripedum quae ova pariunt, ut lacertae. struthocamelus alitum sola ut homo utrimque palpebras habet.156
LVII. Ne genae quidem omnibus, item2 neque nictatio nisi3 his quae animal generant. graviores alitum inferiore gena conivent, eaedem nictantur ab angulis membrana obeunte. columbae et similia utraque conivent. at quadripedes quae ova pariunt, ut testudines, crocodili, inferiore tantum, sine ulla
eyes have less keen sight than those whose eyes are moist. It is stated that if one removes the eyes of young snakes and swallow chicks, they grow again. The eyes of all insects and of creatures with a covering of shell move like the ears of quadrupeds. Those with fragile coverings have hard eyes. All such creatures, and also fish and insects, have no eyelids and do not close their eyes; withal the eye is covered with a membrane that is transparent like glass.
LVI. Human beings have eyelashes on both eye-lids.The eye lashes. Women actually have them dyed every day: such is their desire to achieve beauty that they colour even their eyes; but really the lashes were bestowed by nature for another purpose, as a sort of fence to the sight and a barrier projecting against insects meeting the eye, or other things accidentally falling into them. It is said that sexual excess causes them to drop off, not undeservedly. None of the other species have them excepting those with hair on the rest of the body as well, but quadrupeds have them only on the upper lid, birds on the lower, as also do creatures with a soft skin, for instance snakes, and oviparous quadrupeds, for instance lizards. The ostrich is the only bird with lashes on both eyelids like a human being.
LVII. Not all species have eyelids either, and alsoThe eyelids. only viviparous creatures can wink. The heavier birds close the eye with the lower lid, and also wink with a skin that covers the eye from the corner. Pigeons and similar birds close the eyes with both lids. But oviparous quadrupeds, such as tortoises and crocodiles, do so only with the lower lid, without any winking because their eyes are extremely