40 



INTRODUCTION. 



of the frontal sinuses, and the situation of the cranial cavity, of the Asiatic 

 Elephant. 



With respect to the antrum Highmorianum, or maxillary sinus, this 

 cavity, which communicates laterally with that of the nose, is of moderate 

 size in Man, and is seated above the sockets of the three last molar teeth : 

 in the Simiae it is nearly, if not quite, obliterated. It is of moderate size 

 in the Ox, Goat, and other ruminants ; but does not appear to exist in the 

 Carnivora, and many other animals. In the Ox there are shallow cells 

 between the two tables of the bones forming the palate. 



The last facial recess to be noticed, as containing the organs of 

 one of the senses, is the mouth, in which are seated those of taste. 

 It is covered, or roofed above, by the palatal processes of the supe- 

 rior maxillary bone, and by the two palate bones ; its boundary being 

 circumscribed by the alveolar ridge, or process, of the superior max- 

 illary bone, and by the inferior maxillary, or bone of the lower jaw, 

 including also the teeth. 



In Mammalia, generally, from the Simiae downward, we find two 

 additional bones, separating between the superior maxillary bones, and 

 containing the upper incisor teeth : these two bones are termed the inter- 

 maxillary, and their shape and size are subject to great variation. Though 

 not found separate in the human subject, when adult, or even when very 

 young, they nevertheless exist distinct at an early period of his exist- 

 ence ; but become anchylosed to the maxillary, even before birth : in 

 other Mammalia, however, they retain their distinctiveness. It is in 

 these bones that the tusks (improperly so named) of the Elephant are 

 imbedded. The first tooth on each side, in the true maxillary bones, is 

 the canine, at least, where such a tooth is afforded. The lower jaw in 

 Man, consists of a single bone, and it is the same in the Simiae and Pa- 

 chydermata ; but in most of the Mammalia the lower jaw permanently 

 consists of two elongated portions, united by suture in front, where it 

 presents a retreating angle more or less acute : the space of union 

 between them is termed the symphysis of the lower jaw, and the lower 

 incisor teeth are placed half on one side of it, and half on the other. 



In one respect, this important bone, the lower jaw, which takes so 

 large a part in determining the contour and expression of the face, ex- 

 hibits a character in the human subject to be found in no other animal, viz., 

 that projection at the anterior part, or angle, termed the chin, without 

 which the human face would lose all its dignity, and approximate to the 

 muzzle of the brute. A full and well-formed chin, is one of the points 

 which, in their statues of heroes and gods, the ancients delineated with 

 admirable felicity. 



In Mammalia the lower jaw, of all the bones of the head and face, 

 is alone independently moveable. There is a smooth space, usually more 



