Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1895 edition. Excerpt: ...and others not normally under the control of the will, has been observed in a few cases to go hand in hand with that of a voluntary control of the heart's action.1 Muscles Of The Limbs The palmaris (= p. longus) and its homologue in the hindlimb, the plantaris, are time honoured (and certainly among the best) examples of the gradual degeneration of a muscle. The degeneration of the former has not yet proceeded as far as that of the latter, as is most evident in the fact that while the palmaris still reaches the palmar fascia of the hand, the plantaris only in exceptional cases becomes connected with the homologous plantar fascia of the foot, and in doing so regains its former significance as a flexor of that organ. The plantaris must therefore, as an original flexor, have 1 Cf. E. A. Pease, Boston Med. and Surg. Jour., 30th May 1889. begun to degenerate from the time that the plantar fascia became secondarily attached to the calcaneum, and helped in the formation of the arch of the foot, as the latter became transformed into a supporting organ. But why are the palmaris and plantaris of Anthropoids, in which such transformations do not take place, also in a degenerate condition? It does not appear difficult to answer this question if we consider that these muscles originally extended, as do their homologues in the lower Mammals,1 through the mediation of the palmar or plantar fascia to the phalanges, and acted as common flexors of the fingers and toes. If so, in the course of time--to confine our attention to the hand--as the flexores digitorum communis superficialis and profundus became more extensively and more subtly differentiated from the primitive "pronato-flexor mass" (Humphry), the fibrous terminal expansions of the palmaris...
