82 



August 22nd, 1837. 

 Thomas Bell, Esq., in the Chair. 



Mr. Owen brought before the notice of the Society, through the 

 kindness of Mr. Edward Verreaux, the cranium of an Orang 

 Outang (Simia Wurmbii, Fisch.), exhibiting an intermediate or trans- 

 itional state of dentition, there being in the upper jaw the first or 

 middle incisors, and first and second molares on each side belonging 

 to the permanent series, and the lateral incisors, the canines, and 

 the first and second molares (which are replaced by the bicuspides) 

 belonging to the deciduous series ; and in the lower jaw, both the 

 middle and lateral incisors, and first and second molares on each side 

 belonging to the permanent series, and the second left lateral de- 

 ciduous incisor (not yet shed), the deciduous canines, and the first 

 and second deciduous molares. 



The permanent teeth, which were in place, corresponded in size 

 with those of the great Pongo of Wurmb, and prove that the Orang 

 differs from man in the order of succession of the permanent teeth, 

 having the second true molar, (or fourth if the bicuspides are reckoned 

 as molars), in place before the appearance of the permanent canines. 



Mr. Owen remarked, that the intermaxillary suture still remained 

 unobliterated in the immature cranium exhibited, and he conceived 

 that the ultimate obliteration might be caused by the increased vas- 

 cularity of the parts during the protrusion of the great laniary teeth. 

 In the Chimpanzee this obliteration takes place at a much earlier 

 period. 



Although the marks of immaturity, and consequently those which 

 impress an anthropoid character upon the skuU of the Orang, were 

 generally present in the head exhibited, yet, on a comparison of it 

 with the skull of a younger Orang in which all the deciduous teeth 

 were retained, an approach to the condition of the mature cranium 

 might be observed in the greater protrusion of the intermaxillaries, 

 the lengthening of the maxillary bones, a thickening and greater 

 prominence of the external and superior boundary of the orbit, an 

 enlargement and thickening of the malar bone and zygoma, in the 

 commencement of the development of the cranial ridges, and in the 

 widening and deepening of the lower jaw. 



Mr. Owen then directed the attention of the Meeting to an ex- 

 ceedingly interesting preparation of a foetal Kangaroo, with its ac- 

 companying uterine membranes, upon which he proceeded to offer 

 some observations. He remarked, that in a paper read before the 

 Royal Society in 1834, he described the foetus and membranes of a 

 Kangaroo (Macropus major), at about the middle period of uterine 

 gestation, which in that animal lasts thirty -eight days. In tliis in- 

 stance the condition of the membranes, and the relation of the foetus 

 to the mother, were essentially such as are found to exist throughout 



