50 



INTRODUCTION. 



that the ancients exhibited an overshadowing forehead ; for their tact 

 and discrimination had led them to perceive that, in proportion to the 

 extraordinary development of the muscular powers, are the powers of 

 the sensorium, the capabilities of mental exertion, limited ; and, conse- 

 quently, that a diminished volume of the skull would be conjoined with 

 limbs displaying the beau-ideal of animal force. Their observance of, 

 and adherence to, nature, in this point, are exemplified in the statues of 

 Atliletse, of Hercules, and of the Gladiators. 



But the inapplicability of the facial angle, to the lower orders of 

 Mammalia, must be very manifest to any one who reflects, for a moment, 

 upon the magnitude of the frontal sinuses, which, in so many instances 

 (as in the Elephant, see fig. 20), give to the forehead an air of deceptive 

 projection: besides this, there is another circumstance which militates 

 against this test as being generally applicable. In numerous animals, and 

 especially in the rodents, the nasal cavities are raised so much, and occupy 

 so large a space, that the cranium falls, as it were, behind them, without 

 the slightest anterior elevation ; so that it would be impossible to deter- 

 mine through what points the facial line should pass. Nor is this all ; 

 for even where it is applicable, it is not a sure test, inasmuch as it is sub- 

 ject to great alteration during the progress of the animal from infancy to 

 maturity. In the Ape tribe, and especially in the Orang-outan (Simla 

 Satyrus, Linn.), this circumstance is peculiarly striking. The young 

 Orang-outan is remarkable for a well-developed forehead, to which the 



face bears such a just proportion, and 

 is so situated, as to invest the whole 

 with a character and expression 

 closely approaching that of a little 

 Negro ; but, as maturity advances, the 

 bones of the face develop amazingly ; 

 the jaws shoot forward, acquire pro- 

 digious size, and are furnished with 

 large teeth ; the forehead flattens and 

 falls back ; the cranium, as the face enlarges, gradually assuming a more 

 backward position, and the contour of the whole becoming deteriorated and 

 brutalized. Of the extent, to which this change in the Orang-outan is 

 carried, the annexed sketches (figs. 33 and 34) will convey a better idea 

 than mere verbal description. 



After all, as a test, by which to determine the relative proportion 

 which the face bears to the cranium, the facial angle is altogether 

 insufficient : a much more correct and satisfactory mode has, therefore, 

 been proposed, which consists in making a longitudinal vertical section 

 of the whole head, and measuring the respective areas which the skull 

 and face occupy, the lower jaw being excluded. (See fig. 16, for a 



Skull of youug Oranjj. 



Skull of adult Oraiig. 



