On the classification of Mammalia / by Charles Girard.

  • Girard, Charles, 1822-1895.
Date:
[1851]
Catalogue details

Licence: Public Domain Mark

Credit: On the classification of Mammalia / by Charles Girard. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    1/22 (page 319)
    ' ZOOLOGY. 8. On the Classification op Mammalia. By Charles Girard, of Washington. I. The limits of the class of Mammalia were not clearly understood by tlie earlier naturalists. Some groups, which in former times were referred to other classes (as Cetacea and Bats), have successively been brought into it. None, however, originally placed in this class have ever required removal elsewhere. Thus the progressive investiga- tions has always increased the number of the representatives of this class. At the present day, we may safely say that we know all the essen- tial gi-oups of the class of Mammalia, the actual limits of which are acknowledged by every naturalist. Indeed, w^e must expect many •additional species and genera which time and labor will bring to light, either in a fossil state from various depths in the strata which constitute the solid crust of our globef, or else from its actual surface, and belonging to the living fauna contemporary with the human races. -Such additions are not expected to change or modify the boundaries .of the class, though they may have some importance in the subdivi- ■eions and methodical arrangement of the minor groups. The division of the class into secondary or minor groups, th^ •relationship and subordination of the latter, have attracted the at- tention of all general writers on zoology. Almost every one hap attempted a classification in accordance with the value attributed to one series of characters, rather than to another. The most ancient authors seem to have occupied themselves but little with zoological characters : hence the subdivisions which they establish among Mammalia are based upon their mode of life, or the elements in which they live. Next we see the subdivisions based upon external characters, the 'most striking being selected, such as the locomotive members. ' All this prior to the eighteenth century. Towards the end of that very century, however, comparative ana- tomy started as a science ; and at the beginning of the nineteenth, it introduced an entirely new method of classification. Systematic zoology underwent a metamorphosis. The first half of the present century had not yet elapsed, when