Note bb — BOOK IV.

There is besides this large opening of the Pupil, in some nocturnal Animals, another admirable Provision, enabling them to catch their Prey in the Dark; and that is a Radiation of the Eyes: Of which Dr. Willis thus; Hujus usus est Oculi Pupillam, quasi jubare insito, illuminare, ut res noctu, & in tenebris positas conspicere valeat: quare in Fele plurimùm illustris est: at Homini, Avibus, & Piscibus deest. This Illumination he speaks of, is from the Tapetum, in the Bottom of the Eye, or the shining of the Retina, round the optick Nerve.

Besides which, he saith, the Iris hath a Faculty also, in some, of darting out Rays of Light, so as to enable them to see in the Dark: Of which he tells this Story; Novi quendam cerebro calidiori præditum, qui post uberiorem vini generosi potum in nocte atratâ, sive tenebris profundis, literas distincte legere potuit. Cujus ratio videtur esse, quòd spiritus animales velut accensi, adeòque ab hâc Iride irradiantes, jubare infito Medium illuminabant. Willis Ibid.

Such another Thing, Pliny tells us, was reported of Tiberius Cæsar: Ferunt Tib. Cæs. nec alii genitorum mortalium, fuisse naturam, ut expergefactus noctu paulisper, haud alio modo quam luce clarâ, contueretur omnia. Nat. Hist. l. 11. c. 37.

So Dr. Briggs: Virum sanè calidæ indolis novi in Comitatu Bedfordiensi degentem, qui oculis felineis——donatus est: adeò ut epistolam——mirè admodùm in loco obscuro (ubi eadem mihi vix apparuit) perlegit. Hujus verò Oculi (nisi quod Pupillas insigniores obsinuere) ab aliorum formatione neutiquam discrepabant. Ophthal. c. 5. §. 12.