HOMOLOGIE8 OF THE LIMBS. 



81 



their diverging in different ways as they develop from 

 their primitive simplicity; as both may be regarded as 

 modifications of the same original structure, they are ho- 



4- 



FIG. 32. The skeleton of the arm and leg. H. the humerus: Cd, its articular 

 head which fits into the glenoid fossa of the scapula; (7, the ulna; R, the ra 

 dius; O, the olecranon; Fe, the femur; P, the patella; Fi, the fibula; T, the 

 tibia. 



mologous. The pelvic girdle clearly corresponds generally 

 to the pectoral arch, the tibia and fibula to the radius and 



