[Sidenote: Incredible stories of animals.] But as a rule Neckam’s treatment of animals is far more credulous than sceptical. He believes that the barnacle bird is generated from fir-wood which has been soaked in the salt water for a long time,[600] and that the wren, after it has been killed and is being roasted, turns itself on the spit.[601] He tells a number of delightful but incredible stories in which animals display remarkable sagacity and manifest emotions and motives similar to those of human beings. Some of these tales concern particular pets or wild beasts; others are of the habits of a species. The hawk, for example, keeps warm on wintry nights by seizing some other bird in its claws and holding it tight against its own body; but when day returns it gratefully releases this bird and satisfies its morning appetite upon some other victim.[602] Neckam also shares the common belief that animals were acquainted with the medicinal virtues of herbs. When the weasel is wounded by a venomous animal, it hastens to seek salubrious plants. For “educated by nature, it knows the virtues of herbs, although it has neither studied medicine at Salerno nor been drilled in the schools at Montpellier.”[603] [Sidenote: A chapter on the cock.] Neckam’s chapter on the barnyard cock perhaps will illustrate the divergences between medieval and modern science as well as any other. As a rooster approaches old age, he sometimes lays an egg upon which a toad sits, and from which is hatched the basilisk. How is it that the cock “distinguishes the hours by his song”? From great heat ebullition of the humors within the said bird arises, it produces saltiness, the saltiness causes itching, from the itching comes tickling, from the tickling comes delectation, and delectation excites one to song. Now nature sets certain periods to the movements of humors and therefore the cock crows at certain hours. But why have roosters crests and hens not? This is because of their very moist brains and the presence near the top of their heads of some bones which are not firmly joined. So the gross humor arising from the humidity escapes through the openings and produces the crest.[604] [Sidenote: Effect of sin upon nature.] Neckam harbored the notion, which we met long before in the pagan Philostratus, in the Hebraic Enoch literature, in the Christian _Pseudo-Clementines_ and Basil’s _Hexaemeron_, and more recently in the writings of Hildegard, that man’s sin has its physical effects upon nature. To Adam’s fall he attributes not only the spots on the moon but the wildness of most animals, and the existence of insects to plague, and venomous animals to poison, and diseases to injure mankind.[605] But for the fall of man, moreover, all living creatures would be subsisting upon a vegetarian diet. [Sidenote: Neckam on occult virtues.]