60 ANTHROPOID APES. 



AYhen we consider the internal form of the skull 

 of an aged male gorilla, the first thing that strikes 

 us is the marked development of the frontal 

 sinuses, and especially their width in the region of 

 the nasal portion of the frontal bone. We next 

 observe the wings of the sphenoid bone, and that 

 these large concave apophyses are provided with 

 spaces only slightly separated from each other. 

 These sinuses are not only plainly connected with 

 each other, but with the sphenoidal sinuses. There 

 is a broad sinus in the malar bone, provided with 

 vestibules, and this has a deep communication with 

 the maxillary sinus, or antrum of Highmore, em- 

 bedded in the body of the upper maxillary bone. 

 Tiiere are, finally, sinuses at tl e point of junction 

 between the coronal and occipital crests. 



The maxillary region of the cranium of the young 

 male gorilla is already somewhat prognathous, and 

 the keel-shaped elevation of the bridge of the nose 

 is also very apparent, but the development of these 

 parts is not nearly so advanced as in the aged male. 

 The whole contour of the cranium is oval, and with- 

 out the high crests so chara<'teristic of the aged 

 male animal. It is well known that the Swedish 

 anatomist and anthropologist Anders Ketzius has 

 classified the skulls of different races of men as long- 

 headed {doUchocephali) and short-headed (brachy- 

 eephali). In the former class, the length is consider- 

 ably greater than the height ; while in the latter, the 

 difference is either slight or non-existent. The 

 skulls of the doliohocephali are long and oval ; those 

 of the brachycephali are short, round, or sqnure. In 



