Neither need we seek any other reason for the number of these skins, save only that the opening of the veinous artery, being oval-wise, by reason of its situation, may be fitly shut with two; whereas the other, being round, may the better be clos'd with three.
Eta mintz hauen kopuruari dagokionez ez dago honako hau baino arrazoi gehiago bilatu beharrik: zain arteriaren irekidura, bera dagoen lekuagatik, erosoago itxi ahal dela birekin, obala delako; besteak hirurekin hobe itxi daitezkeen artean, borobilak direlako.