204 THE STRUCTURE OF MAN 
Disposition of the foot at a sharp angle to the leg. 
Secondary separation of the orbit from the fossa temporalis. 
Shifting of the lachrymal bone on to the surface of the face. 
The disposition of the palatine bones in relation to the 
palatal processus of the maxilla. : 
The fusion of the nasal bones. 
The position of the pinna on the adult head. 
The ultimate positions of the ribs upon the vertebral column. 
(Widening of the thorax, as an accompaniment of an altera- 
tion in the positions of the organs within the thoracic cavity.) 
II. ORGANS SHOWING PROGRESSIVE CHARACTERS, 2.¢. TENDING 
TOWARDS MORE PERFECT ADAPTATION 
Higher differentiation and more subtle development of the 
muscles of the thumb—both of those which pass from the fore- 
arm along the volar and dorsal surfaces to the thumb, and of 
those of the ball of the thumb. 
Increase in physiological efficiency of the hand in general, 
especially of the flexors of the hand and of the fingers, the palmaris 
longus excepted. 
Increased development and strengthening of the arch of the 
foot, of the tarsus, heel, and great toe. 
Secondary lateral extension of the malleolus fibularis. 
The perfecting of the whole lower limbs for support and 
ambulation (in adaptation to the upright gait). 
Development of the iliac expansions in the female, with 
widening of the sacrum and of the aperture of the pelvis. 
Cana nhe of the lumbar vertebral column. 
Gluteal muscles and muscles of the calf (gastrocnemius and 
soleus). 
More subtle differentiation of the facial muscles proper (as 
opposed to the muscles of the pinna and of the scalp). 
The projectile nose. 
Certain nerve tracts in the brain and spinal cord. 
The occipital lobes of the brain (posterior cornua of lateral 
ventricle and calcar avis ?) 
Higher degree of development of the brain cortex (histological 
differentiation concomitant with increasing intelligence). 
The more subtle differentiation of the muscles of the larynx. 
Articulate speech. 
