﻿EXTERNAL ANATOMY. EARS. 47 



below, we must be allowed to question the accuracy of 

 the statement: it wears every appearance of exaggera- 

 tion, and obviously cannot be proved. That most of 

 the rapacious tribes, on the other hand, possess a length 

 of sight, if we may use the term, far superior to all other 

 birds, is proved by the additional means given to them 

 for that purpose, in the structure of the eyebrows, or 

 superciliary ridge, which, in these birds, projects over 

 the eyes, to which they act as a screen from the vertical 

 rays of light, and concentrates their powers in viewing 

 objects placed before or beneath them. This structure is 

 also apparent in the horned owls and eagle owls (Otus, 

 Nycted), but is not found in those of the restricted genus 

 Strioc, 



(51.) The Ears of birds, excepting those of the owls, 

 exhibit to outward appearance very little variation. M. 

 Cuvier remarks, that nocturnal birds alone have a large 

 external ear, which nevertheless is not so prominent as 

 that of quadrupeds. This statement is so vague as to 

 require some explanation. The ears of a sparrow or a 

 hawk are just as external as those of an owl, seeing 

 that in neither of these birds can they be discovered 

 unless the feathers are carefully removed ; whereas, when 

 we speak of an external ear, 

 we annex the idea of its being 

 prominent, like that of the 

 majority of quadrupeds. Now, 

 there is only one bird yet dis- 

 covered, whose ear, in this 

 sense, can be called external ; 

 and this is XheL'Oricou of Le 

 Vaillant* (^r. 21.), a large 

 species of vulture, discovered 

 by him in Southern Africa, 

 and subsequently named by methodists Vultur auricu- 

 lar is; the ear, in this singular bird, appears truly external, 



* Ois. d'Afrique, vol. i. pi. 9. Some ornithologists are of opinion that 

 this prolongation is the mere effect of leanness, or of old age, as wrinkles 

 are on the human face; but this theory wants confirmation. 



