The ancients entertained a strong belief that birds were gifted with the knowledge of herbs, and that just as the Woodpecker and Hoopoe sought out the Springwort, wherewith to remove obstructions, so other birds made use of certain herbs which they knew possessed valuable medicinal or curative properties; thus Aristotle, Pliny, Dioscorides, and the old herbalists and botanical writers, all concur in stating that Swallows were in the habit of plucking Celandine (_Chelidonium_), and applying it to the eyes of their young, because, as Gerarde tells us, “With this herbe the dams restore sight to their young ones when their eies be put out.” W. Coles, fully accepting the fact as beyond cavil, thus moralizes upon it:--“It is known to such as have skill of nature what wonderful care she takes of the smallest creatures, giving to them a knowledge of medicine to help themselves, if haply diseases annoy them. The Swallow cureth her dim eyes with Celandine; the Wesell knoweth well the virtue of Herb Grace; the Dove the Verven; the Dogge dischargeth his mawe with a kind of Grasse; ... and too long it were to reckon up all the medicines which the beestes are known to use by Nature’s direction only.” The same writer, in his ‘Adam and Eden,’ tells us that the _Euphrasia_, or Eyebright, derived its English name from the fact of its being used by Linnets and other birds to clear their sight. Says he: “Divers authors write that Goldfinches, Linnets, and some other birds make use of this herb for the repairing of their young ones’ sight. The purple and yellow spots and stripes which are upon the flowers of Eyebright very much resemble the diseases of the eyes, or bloodshot.” Apuleius tells us that the Eagle, when he wishes to soar high and scan far and wide, plucks a wild Lettuce, and expressing the juice, rubs with it his eyes, which in consequence become wonderfully clear and far-seeing. The Hawk, for a similar purpose, was thought to employ the Hawk-bit, or Hawk-weed (_Hieracium_). Pigeons and Doves, not to be behind their traditional enemy, discovered that Vervain possessed the power of curing dimness of vision, and were not slow to use it with that object: hence the plant obtained the name of Pigeon’s-grass. Geese were thought to “help their diseases” with _Galium aparine_, called on that account Goose-grass; and they are said to sometimes feed on the _Potentilla anserina_, or Goose Tansy. On the other hand, they were so averse to the herb known to the ancients as _Chenomychon_, that they took to flight the moment they spied it.