Evolution and disease / by J. Bland Sutton ; with 136 illustrations.

Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Evolution and disease / by J. Bland Sutton ; with 136 illustrations. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    exhibited to a class of students, this large second toe was mistaken for the hallux (fig. 8). This observation is of interest, the large size of the first toe and the great development of its muscles are owing to the greater use and importance of the hallux in mammals which main- tain an erect, or semi-erect, position when walking along the ground as in man, or climbing trees as in monkeys and phalangers. Humphry, in reference to the large development of this toe, says, Man literally stands in the animal world on his great toe. Fig. 8.—Enlargement of the second toe subsequent to amputation of the hallux. The same remarks apply to the thumb: in man increased function develops its special muscles, thickens the bone, and toughens the nail. Even among quadru- mana the pollex may be absent (Ateles) ; in such a high form as the chimpanzee the thumb is slender, short, and insignificant. In man we may attribute the dispropor- tion of the hallux and pollex, in comparison with the neighbouring digits, to inheritance through a long line of ancestors of gradual increments of size induced by