358 



TIIK SENSORIAL FUNCTIONS. 



tiidinal section of the cavity of the human nostril, 

 where they are seen covered by the Schneiderian 

 membrane.* A transverse and vertical section of 

 these parts is given in Fig. '383. 1 The turbinated 



bones are curiously folded, and often convoluted in 

 a spiral form, with the evident design of obtaining 

 as great an extent of surface as possible within 

 the confined space of the nasal cavity. This tur- 

 binated or spiral shape, chiefly characterises these 

 bones among herbivorous quadrupeds : in the 



* This figure shows the branches of the olfactory nerve (o), pass- 

 ing through the thin cribriform plate of the ethmoid bone, and 

 distributed over that membrane. Several of the cells, which open 

 into the cavity, are also seen ; such as the large sphenoidal sinus (s), 

 the frontal sinus (f), and one of the ethmoidal cells (c). n is the 

 nasal bone ; p, the palate ; and e, the mouth of the Eustachian 

 tnbe, which leads to the ear. 



t In this figure, s, is the septum, or partition of the nostrils, on 

 each side of which are seen the sections of the turbinated bones 

 ])rojecting into the cavity ; the ethmoid cells (c), situated between 

 llie orbits (o) ; and the Antrum maxillare (a), which is another 

 large cavity communicating with the nostrils. 



