210 THE SEASON VHY. 



" And the Lord God formed man of the dust of the ground, and breathed into 

 his nostrils the breath of life ; and man became a living soul." GENESIS u. 



contact with the filaments of the olfactory nerve, which are spread 

 out upon the walls of the nostrils, and those nerves transmit 

 impressions to the brain, constituting what we call the odour of 

 substances. 



Fig. 66. BKOWITSIQ THE DISTEIBUTION OF THE NEBVOUS FILAMENTS UPON 

 SENSITIVE MEMBBANES. 



A. The olfactory nerve, distributed in minute branches upon the membrane 

 of the nostril. 



B. The bulb of the olfactory nerve. 



C. The roots from which the olfactory nerve originates. 



D E. Nerves of the palate, showing the manner in which they are passed 

 through the bones of the roof of the mouth. 



993. Why do hairs grow across the passages of the 

 nostrils ? 



Because they form a defence against the admission of dust and 

 insects, which would otherwise frequently irritate i^e nenrous 

 Btructure of the nose. 



994. Why are the nostrils directed downwards t 

 Because, as odours and effluvia ascend, the nose is directed 



