406 THE SENSORIAL FUNCTIONS. 



tion: They are seen in Fig. 387, passing out 

 through the orbit of the eye (o) in two large 



branches, an upper one (u), and a lower one (l), 

 the ramifications of which are spread over the 

 mandibles, both within and without. For the 

 protection of the highly sensible extremity of 

 the beak against the injurious impressions of 

 hard bodies, a horny process (p), similar, both in 

 form and office, to the human nail, is attached to 

 it, and its edges guarded by a narrow border of 

 the same horny material ; these receive a first, 

 and fainter impression, and admonish the animal 

 of approaching danger ; if none occur, the mat- 

 ter is then submitted to the immediate scrutiny 

 of the nerves themselves, and is swallowed or 

 rejected according to their indication.* 



It has been generally asserted that Vultures, 

 and other birds of prey, are gifted with a highly 

 acute sense of smell ; and that they can discover 

 by means of it the carcass of a dead animal at 

 great distances : but it appears to be now suffi- 



* Such is the account given by Sir Busick Harwood, in his 

 " System of Comparative Anatomy and Physiology," p. 26. 



