4 
PRIMROSE : THE ANATOMY OF THE ORANG OUTANG 
peculiarities, and we then possess the true means of appreciating those 
modifications by which a material organism is especially adapted to 
become the seat and instrument of a rational and responsible soul.” 
Owen states that “ the Orangs, or tailless apes of Africa and Asia, 
have long been recognized as the mammalia which make the closest 
approach to man ; and their organization has therefore been studied 
with more or less care and detail by many distinguished physiologists 
and comparative anatomists.” This statement indicates the interest 
which had been manifested in the study of the anthropoid apes, more 
than half a century ago. 
In addition to the Orang Outang, the group of anthropoid apes 
includes the Gorilla and the Chimpanzee, which inhabit chiefly the west 
coast of Africa, and the Gibbon, which is found in the Indian Archi- 
pelago and some parts of the adjoining mainland. 
The Orang Outang is found in the islands of Borneo and Sumatra. It 
would appear that the creature never attains a great size. Huxley 
remarks that there is no evidence that they exceed 4 feet 4 inches in 
height. On the other hand, Rudolf Pick states that Clark Abel is 
reported to have found a species of Orang in Sumatra which reached 
the height of two metres ; this, however. Pick considers a gross exag- 
geration. 
The specimen which I am about to describe was that of a young male 
animal (reproductions from photographs of the animal are published 
herewith). It measured 57 cm. in height. No history of its previous life 
and habits could be obtained. The shape of the cranium approaches, 
in many particulars, the human type. As has been pointed out by 
Hartmann^ and others, the young apes approach more closely to the 
human type of skeleton than do the aged apes. Thus the great bony 
crests which are so characteristic of the skull of an aged male Gorilla 
are absent in young specimens. In all the smaller and middle-sized 
monkeys the general surface of the calvaria is oval and smooth, and 
remains so throughout life, whilst in the larger Baboons and Orangs 
there are well-marked supraorbital, sagittal, and occipital ridges.^ 
These are said to attain their greatest development in the aged male 
Gorilla, where, as Plower asserts, they completely mask the original 
form of the cranium. In my specimen (a young animal) the surface of 
the cranium was perfectly smooth, and in this respect resembled the 
skull of a man, as there were no indications of crests. 
It would appear, however, that the bony crests develop in connection 
I Robert Hartmann, “Anthropoid Apes.” New York, 1886, p. 107. 
* W. H. Flower, “ An Introduction to the Osteology of the Mammalia.” London, 1885, p. 162. 
