136 ANDREW JACKSON HOWE. 



among vertebrates ; and our own hands and feet pre- 

 sent these digits in a high degree of perfection. Our 

 fingers, with the opposable thumb, are not equaled in 

 function by the digital development reached by any 

 other animal. Man has been classed alone as bimanous, 

 on account of his possessing two hands. A unity of 

 method in the construction of the carpal and tarsal ter- 

 minations is strikingly apparent not only in the higher, 

 but in the lower vertebrates, fishes alone forming ex- 

 ceptions. The pentadactyl has a wide range of appli- 

 cation it reaches reptiles as well as walking, swim- 

 ming, and flying mammals. Divergencies are common, 

 for the necessities of modified organizations enforce 

 variety. The herbivora must have feet and legs suited 

 to their manner of living; and the carnivora need 

 digital terminations which shall enable them to cap- 

 ture and tear in pieces their prey. If the claw be 

 sharp its point is protected by a sheath and by being 

 raised from the ground. Amphibious animals adhere 

 quite closely to the pentadactyl type, though their 

 digits may be concealed by a web. Birds apparently 

 depart considerably from the prevailing order of digital 

 division, yet in their legs and wings may be found the 

 evidence that they are constructed in accordance with 

 the somewhat rigid formula. 



Variations of digital termination can not be fully 

 comprehended without considering, anatomically and 

 functionally, all the bones which constitute what are 

 denominated the shoulder and pelvic girdles. In an 

 anterior limb may be found a scapula, humerus, radius 

 and ulna, and carpal and metacarpal bones, to which 

 the phalanges are attached ; and the greater the num- 

 ber of digits, the nearer certain it is that a distinct 

 ulna and the usual complement of metacarpal bones 



