FISCHER ON THE PELVIS OF THE MAMMALIA. 15 



wanting in man. The greater length of the os ilium makes the conjugate dia- 

 meter of the pelvis greater than the transverse. 



Section 9. 3. The os ischium in them also consists of an ascending and a 

 descending ramus. In man, the ischiatic spine is in the descending ramus, 

 which according to Meyer,* and Josephi, f the quadrumana have not, but in 

 its place a rough protuberance (as perhaps in all animals. Autenreith.) The 

 tuberosity of the ischium, on the other hand, is longer and broader in the 

 quadrumana, projecting more outwards and anteriorly, and especially remark- 

 able in the sirnia lar, the sylvanus, and the papio marmon. The ascending 

 ramus is more slender and narrower ; it ascends to the union with the os 

 pubis at a wider angle than in man. 



Section 10. The acetabulurn is composed of these three bones, the greater 

 part by the ilium and ischium, the smaller part by the pubis, and therefore it 

 might happen that, in some species, the os pubis haa no share in the formation 

 of the acetabulum. This fact is contended for by Cunauld J and Meyer, || but 

 Joseph! doubts their opinion. (In the cercopithecus alluded to, the os pubis 

 .distinctly forms a portion of the acetabulum. Autenreitn.) The acetabulum 

 in the quadrumana is much more distant from the crest of the os ilium and 

 nearer to the sacrum, (as in all animals, Autenreith), but in other respects 

 differs little from the human, unless it be that the incisura of the acetabulum 

 is deeper and extends further towards the os ischium. 



Section 11. Behind the acetabulum forwards, and downwards, the foramen 

 ovale is formed by the union of the os pubis and ischium. This foramen in 

 the quadrumana, with reference to the whole animal, is more and more oblong, 

 and is largest and almost round in the cercopithecus jaccho. The foramen ovale 

 can only be said to be larger in the quadrumana than in man, when the cavity 

 of the pelvis is compared with the area of the foramen, but it is less, if the size 

 of the whole animal be compared to it. Of all mammalia, man has the largest 

 pelvis, compared with the size of the whole body, and hence also it may arise 

 that he has the largest foramen ovale. It is still larger in woman, although 

 shorter than in man. In a male skeleton of elevated stature, I found the su- 

 perficies of the foramen ovale to be to the total length of the skeleton 



as 991 to 1000; 



In the female skeleton equally regular, as 1101 to 1000 ; 



In the cercopithecus, already so often mentioned, as 357 to 1000 ; 

 In the rabbit, almost of the same size, as 392 to 1000. 



It may be conjectured from these measurements by how much the smaller 

 pelvis in man exceeds that of animals, passing over here in silence the larger 

 pelvis ; this appears to be necessary, as well from his erect position as from 

 the larger size and rounder form of the foetal head. Autenreith.) 



Section 12. 4. Bradypoda. The os sacrum of the bradypi-didactylus, and 

 myrmecophagus didactylus, is composed of four vertebrae. In the myrmeco- 

 phagus didactylus (L.) the spinous processes of the sacrum are of the same 



* Augenehmer und nuzlicher Zeitbertreib mit Betrachtung curioser Vorstellungen aller- 

 hand Thiere, sowal nach ihrer gestalt als auch nach der Accuratess davon verfertigte Struk- 

 tur ihrer Scelete von Job. Dan. Meyer, Miniaturmahler. Niirnberg, 1748. 36. iii. Thle. 

 fol. p. 17. 



t W. Josephi, A. D. S., p. 302. J Memoires de 1'acad. d. Scienc. de Paris. Anno 

 1735, p. 383. || Meyer 1. c., p. Josephi 1. c., p. 305. 



