OCR Text |
Show 74 gether, is the same as in man; but the development of a pair of ribs to the first lumbar vertebra, which is an exceptional occurrence in Man, is the rule in the Gorilla; and hence, as lumbar are distinguished from dorsal vertebrre only by the presence or absence of free ribs, the seventeen "dor~mlumbar'' vertebrre of the Gorilla are divided into thirteen dorsal and four lumbar, while in Man they are twelve dorsal and five lumbar. Not only, however, does Man occasionally possess thirteen pair of ribs,* but the Gorilla sometimes has fourteen pairs, while an Orang-Utan skeleton in the Museul'll of the Royal College of Surgeons has twelve dorsal and five lumbar vertebrre, as in Man. Cuvier notes the same number in a Hylobates. On the other hand, among the lower Apes, many possess twelve dorsal and six or seven lumbar vertebrre; the Douroucouli has fourteen dorsal and eight lumbar, and a Lemur (Stenops tardigradus) has fifteen dorsal and nine lumbar vertebrre. The vertebral column of the Gorilla, as a whole, differs from that of Man in the less marked character of its curves, especially in the slighter convexity of the lumbar region. Nevertheless, the curves are present, and are quite obvious in young skeletons of the Gorilla and Chimpanzee which have been prepared without removal of the ligaments. In young Orangs similarly preserved, on the other hand, the spinal column is either straight, or even concave forwards, throughout the lumbar region. Whether we take these characters then, or such minor ones as those which are derivable from the proportional length of the spines of the cervical vertebrre, and the like, there is * "More than once," says Peter Camper, "have I met with more than six lumbar vertebne in man. . . . Once I found thirteen ribs and four lumbar vertebrre." Fallopius noted thirteen pair of ribs and only four lumbar vertebrre; and Eustachius once found eleven dorsal vertebrre and six lumbar vertebrro. -' CEuvres de Pierre Camper,' T. I, p. 42. As Tyson states, his 'Pygmie' had thirteen pair of ribs and five lumbar vertebrre. The question of the curves of the spinal column in the Apes requires further investigation. no doubt whatsoever as to the marked difference between Man and the Gorilla; but there is as little, that equally marked' differences, of the very same order, obtain between the Gorilla and the lower apes. Gorz'ZZa. flilibon. FIG. 16.-Front and side views of the bony pelvis of Mnn, the Gorilla and Gibbon: reduceclfromdrawings made from nature, ofthe same absolute length, by Mr. Waterhouse Hawkins. |