HUMERUS • DICCIONARIO INGLES.COM • Definition of Humerus

... length which is characteristic of their nearest relations and progenitors.), and this fact perhaps indicates that there is some correlation of the length of the beak with the length of the bones of the wings, in the same manner as with that of the feet and tarsi. The shortening of the humerus and radius in the seventeen birds may probably be attributed to disuse, as in the case of the scapula and furculum to which the wing-bones are attached;—the lengthening of the wing-feathers, and consequently the expansion of the wings from tip to tip, being, on ...

— The Variation of Animals and Plants under Domestication - Volume I • Charles Darwin