BIHDS. 



297 



extent, that in the stomach of one were found pebbles sufficient 

 to fill a large glass bottle ; and as the Ostrich will swallow 

 metals with equal readiness, popular creduhty, in former times, 

 went so far as to assign to it the power of digesting these 

 substances ; and many are the allusions in the older writers 

 to this supposed power of "the iron-eating Ostrich."* 



Fig. 249.— African Ostkicu. 



Senses. — The two senses which appear to be developed in 

 the highest degree in birds are those of sight and of smell. 

 The arrangements connected with the eye, regarded as an 

 optical instrument, are, in all their details, replete with evi- 

 dence of design. It has to perform a variety of functions, 

 and demands a corresponding variety in the adjustment of its 

 several parts. It must be fitted for vision at the altitudes to 

 which birds of prey soar, and equally fitted for vision near at 



* Mr. Bennett, in " Gardens and Menageries," quotes the fiillowinj; lines, 

 as illustrative of the prevalence of the belief. The author is Skellon, a 

 laurelled poet of the reign of Henry the Eighth : — 



" The Estridge that will eate In the steade of meat ; 



An horsehowe' so grcate, Such fer^•ent heat 



> Horseshoe. His stomake doth freat" 



