313 



swallow metals with equal readiness, popular credulity, in 

 former times, went so far as to assign to it tlie 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 OSTRICH. 



Senses. The two senses which appear to he 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 

 hand. It must be adapted for rays of light passing through 



* Mr. Bennett, in Gardens and Menageries, quotes the following lines, 

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

 laurelled poet of the reign of Henry the Eighth : 

 " The Estridge that will eate 

 An horshowe* so greate, 

 In the steade of meat ; 

 Such fervent heat 

 His stomake doth freat." 

 * Horse-shoe. 



