76 THE HUMAN BODY. 



which the nose communicates by the posterior nares (Fig. 30) 

 with the throat-cavity, so that air can pass in or out in breath- 

 ing. 3. The malar bones, or cheek-bones, (Z, Fig. 29.) lying 

 beneath and on the outside of the orbit on each side. 4. The 

 nasal bones (N, Fig. 29), roofing in the nose-. 5. The lach- 

 rymal bones (L, Fig. 29), very small and thin and lying be- 

 tween the nose and orbit. 6. The inferior turbinate bones, 

 lying inside the nose, one in each nostril-chamber. 



The Hyoid. Besides the cranial and facial bones there 

 is, as already pointed out, one other, the hyoid (Fig. 31), 

 which really belongs to the skull, although it lies in the 

 neck. It can be felt in the front of the throat, just above 

 " Adam's apple." The hyoid bone is U-shaped, with its con- 

 vexity turned ventrally, and consists of a 

 body and two pairs of processes called cor- 

 nua. The smaller corima (Fig. 31, 3) are 

 attached to the base of the skull by long 

 Fro. 81. The hyoid ligaments. These ligaments in many ani- 

 great cornua 3 ; ' I mals are represented by bones, so that the 

 small corima. ' hyoid, with them, forms a bony arch at- 

 tached to the base of the skull much as the ribs are attached 

 to the bodies of the vertebrae. In fishes behind this Jiyoidean 

 arch come several others which bear the gills; and in the 

 very young Human Body these also are represented, though 

 they almost entirely disappear long before birth. The hyoid, 

 then, with its cornua and ligaments answers pretty much to 

 a gill-arch, or really to parts of two gill-arches, since the 

 great and small cornua belong to originally separate arches 

 present at an early stage of development. It is a remnant of 

 a structure which has no longer any use in the Human Body; 

 but in the young frog-tadpole parts answering to^it carry 

 gills and have clefts between them which extend into the 

 throat just as in fishes. The gills are lost afterwards and the 

 clefts closed up when the frog gets its lungs and begins to 

 breathe by them. In the embryonic human being these gill- 

 clefts are also present and several more behind them, but the 

 arches between them do not bear gills, and the clefts them- 

 selves are closed long before birth. As they have no use their 

 presence is hard to account for; those who accept the doc- 

 trine of evolution regard them as developmental reminis- 

 cences of an extremely remote ancestor in which they were 

 of functional importance somewhat as in the tadpole: of 



