The error in this conceit consists in the ignorance of these cavities, and their proper use in nature; for this is a particular disposure of parts, and a peculiar conformation whereby these holes and sluces supply the defect of Gils, and are assisted by the conduit in the head; for like cetaceous Animals and Whales, the Lamprie hath a fistula, spout or pipe at the back part of the head, whereat it spurts out water. Nor is it only singular in this formation, but also in many other; as in defect of bones, whereof it hath not one; and for the spine or backbone, a cartilaginous substance without any spondyles, processes or protuberance whatsoever. As also in the provision which Nature hath made for the heart; which in this Animal is very strangely secured, and lies immured in a cartilage or gristly substance. And lastly, in the colour of the liver: which is in the Male of an excellent grass-green: but of a deeper colour in the Female, and will communicate a fresh and durable verdure. CHAPTER XX Of Snayls. Whether _Snayls_ have eyes some Learned men have doubted. For _Scaliger_ terms them but imitations of eyes; and _Aristotle_ upon consequence denyeth them, when he affirms that _Testaceous_ Animals have no eyes. But this now seems sufficiently asserted by the help of exquisite Glasses, which discover those black and atramentous spots or globales to be their eyes. That they have two eyes is the common opinion, but if they have two eyes, we may grant them to have no less than four, that is, two in the larger extensions above, and two in the shorter and lesser horns below, and this number may be allowed in these inferiour and exanguious animals; since we may observe the articulate and latticed eyes in Flies, and nine in some Spiders: And in the great _Phalangium_ Spider of _America_, we plainly number eight. But in sanguineous animals, quadrupeds, bipeds, or man, no such number can be regularly verified, or multiplicity of eyes confirmed. And therefore what hath been under this kind delivered, concerning the plurality, paucity or anomalous situation of eyes, is either monstrous, fabulous, or under things never seen includes good sense or meaning. And so may we receive the figment of _Argus_, who was an Hieroglyphick of heaven, in those centuries of eyes expressing the stars; and their alternate wakings, the vicissitude of day and night. Which strictly taken cannot be admitted; for the subject of sleep is not the eye, but the common sense, which once asleep, all eyes must be at rest. And therefore what is delivered as an Embleme of vigilancy, that the Hare and Lion do sleep with one eye open, doth not evince they are any more awake then if they were both closed. For the open eye beholds in sleep no more then that which is closed; and no more one eye in them then two in other Animals that sleep with both open; as some by disease, and others naturally which have no eye-lids at all.