354 MR. R. OWEN ON THE OSTEOLOGY OF 
finger in length, and is as slender and weak as it is short. The little finger is also 
shorter, as compared with the other fingers, than in the human subject. The meta- 
carpal bones are chiefly remarkable for their length ; the phalanges both for their length 
and their anterior curvature. The hand is thus admirably formed for clasping the thick 
boughs of forest trees. The ridges on the sides of the anterior surface of the first and 
second phalanges are well developed to afford attachment to the fascie, which restrain the 
starting of the flexor tendons during the powerful actions of the muscles of the fore arm. 
§ 2. Osteology of the young Chimpanzee. 
In consequence of the early period at which the brain acquires its full size, the 
cranial portion of the skull of the young Chimpanzee greatly preponderates over the 
facial or maxillary part when the small deciduous teeth only are developed. At that 
period, therefore, it proportionally approximates towards the human form: the facial 
angle is more open; the occipital foramen is more central, and its plane more hori- 
zontal ; the slender zygomata, as seen from below, are confined to the anterior moiety of 
the skull; and altogether the resemblance to the human cranium is startlingly close. 
The difference, on the other hand, between the young and the old skulls is such, that 
a naturalist, unaware of the changes of form which the jaws undergo as they acquire 
their permanent set of teeth, might fail to recognise them as belonging to the same spe- 
cies, and might still entertain doubts as to the specific identity subsisting between the 
baboon-like skull of the adult and the anthropoid one of the young Chimpanzee, which 
he had previously been accustomed to consider as characteristic of the species. These 
doubts, which I entertained myself on the first inspection of the adult skeleton, were, 
however, in a great degree removed by perceiving the correspondence which prevailed in 
the two skeletons in the forms and proportions of the extremities, the number of vertebre 
and ribs, the structure of the sternum and scapula, &c. But to derive further confirmation 
of their identity, I compared the crowns of the permanent teeth! which were lodged within 
the jaws of the young Chimpanzee, with those which had replaced the deciduous set in 
the adult skull. The resemblance in point of figure and size was exact, and showed that 
the Pygmy of Tyson must ultimately acquire teeth which would necessarily induce those 
changes of form in the jaws upon-which the differences in question chiefly depended. 
The germs of the permanent teeth are placed with singular irregularity within the 
jaws ; the second incisor is situated directly behind the first; and the apew of the 
crown of the laniary is lodged deep in the jaws, below the first bicuspis. Both bicuspides 
are, however, lodged conveniently below the crowns of the deciduous molares. Their 
crowns were completely formed, and the first true molar had taken its place in the jaw 
in the specimen examined, but its fangs were open and incomplete. The crown of the 
second molar was completely formed, and corresponded to the dimensions of the second 
molar in the adult skull: the germ of the third molar was not yet apparent, The suc- 
' See Plates LI. and LII., a, b, c, d, e, f, g. 

