NATURAL THEOLOGY. 291 



position: which operations compensate for the de- 

 crepitude of its legs and feet. Without her hook, 

 the bat would be the most helpless of all animals. 

 She can neither run upon her feet, nor raise her- 

 self from the ground. These inabilities are made 

 up to her by the contrivance in her wing ; and in 

 placing a claw on that part, the Creator has de- 

 viated from the analogy observed in winged 

 animals. A singular defect required a singular 

 substitute. 



III. The crane kind are to live and seek their 

 food amongst the waters ; yet, having now^eb-foot, 

 are incapable of swimming. To make up for this 

 deficiency, they are furnished with long legs for 

 wading, or long bills for groping, or usually with 

 both. This is compensation. But I think the 

 true reflection upon the present instance is, how 

 every part of nature is tenanted by appropriate 

 inhabitants. Not only is the surface of deep 

 waters peopled by numerous tribes of birds that 

 swim, but marshes and shallow pools are fur- 

 nished with hardly less numerous tribes of birds 

 that wade. 



IV. The common|?«rro^has, in the structure of 

 its beak, both an inconveniency and a competisa- 

 tion for it. When I speak of an inconveniency I 

 have a view to a dilemma which frequently occurs 

 in the works of nature — viz., that the peculiarity 

 of structure by which an organ is made to answer 

 one purpose necessarily unfits it for some other 

 purpose. This is the case before us. The upper 



