A comparison of the shoulder bones and muscles with the pelvic bones and muscles / by Professor Humphry.

  • Humphry, George Murray, Sir, 1820-1896.
Date:
[1870?]
Catalogue details

Licence: Public Domain Mark

Credit: A comparison of the shoulder bones and muscles with the pelvic bones and muscles / by Professor Humphry. Source: Wellcome Collection.

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    A COMPARISON OF THE SHOULDER BONES AND MUSCLES WITH THE PELVIC BONES AND MUSCLES. By Professor Humphry, (PL III.) Professor Flower’s paper “ On the Correspondence between the parts composing the Shoulder and the Pelvic Girdles of the Mammalia,” contained in the last Number of this Journal, has induced me to reconsider the subject; and the conclusions at which I arrive do not entirely accord with those of Professor Flower, or with those to which, as he intimates, I myself in some degree formerly inclined. The fact of its being a trite subject, which has been handled by many and able anatomists, proves that it is a difficult one, and therefore interesting; and it is moreover interesting because several of the great principles of animal construction, that is, of morphology and homology, are involved in it. It is quite clear that the fore and the hind limbs are in the main alike; yet a certain amount of dissimi¬ larity pervades every part of them in every animal, adapts each to its special purposes, and is therefore least at the middle, and most marked in the proximal and distal parts of the limbs. The same remarks apply to the limbs in the several members of the vertebrate division. Throughout, variety is grafted upon uniformity. The object of the variety is conformity to the special purposes of the limb, and adaptability to the varieties— that is, the peculiarities—of the several animals. Unfailing in result and regulated by some utterly unknown force, it offers innumerable problems to the homologist, many of which are difficult and some perhaps impossible of solution. When we remember how hard it is correctly to compare the several pro¬ cesses in two distant vertebrae of the same spinal column, although we have the aid afforded by all the gradations pre¬ sented in the intervening vertebrae, we cannot be surprised that a successful comparison of two limbs placed at opposite ends of the trunk, with different movements and functions, and unconnected by intermediate gradations, has not yet been made. The difficulty of instituting a correct homological com¬ parison is augmented by the fact that the deviations from one another, or of both from a simple and common original, are