Strangeways' veterinary anatomy.

Date:
1879
Catalogue details

Licence: Public Domain Mark

Credit: Strangeways' veterinary anatomy. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    preceding its birth. In this work the vaxious departments are discussed in the order here given. The structures which are subjects of the first three divisions are sometimes classed together as the Organs of Locomotion, for bones form the framework of the body and often act as levers; the joints connect the bones, permitting more or less motion between them, while the muscles move the bones, and so produce motion of a part of the body—or it may be locomotion, or change of situation in the entire frame. In the study of Comparative Anatomy the terms analogy and homology are frequently met with. Although these words are not unfrequently used indiscriminately, the difference in their significations is suflSciently clear. Two structures are said to be analogous when, though differing in structure, they perform the same function ; but when their functions are different, while, in the broad sense, they correspond in structure or form, they are said to be homologous. Thus the middle finger of the human hand is the homologue of the anterior digit of a horse, because they have the same general structure and relation to the rest of the limb; but as the functions they perform are quite dissimilar, they cannot be termed analogous. Again, the lungs of a mammal are analogous to the gills of a fish, for, though they differ widely in structure and form, and are therefore not homologous, their ultimate use is the same—each of them being an apparatus in which is carried on the process of purifying the blood.