246 THE INTEGUMENT AND OEGANS OF 



tactile sensibility, as well as by its full physiological relations 

 to temperature, pressure, and muscular action. In no animal 

 are the tactile arrangements on the distal portions of the limbs 

 so fully developed as in man. No form of ape exhibits the 

 same complex and relatively minute arrangement of tactile 

 ridges as in the human hands and feet. These ridges have 

 centres of evolution and angular points of convergence, as is 

 the case with the hair in other localities. In the human 

 hand, the tactile ridges at the points of the fingers are very 

 complicated, and relatively minute. In the human foot, the 

 great tactile area is on the outer pad of the foot. The sensi- 

 bility of the human sole is of primary importance in locomo- 

 tion, as in man two limbs only are employed, and the body is 

 occasionally even balanced only on one foot. 



n. Finally, the human integument is directly developed in 

 reference to the intellectual and emotional phases of his con- 

 stitution. 



2. — Smell and Taste. 



a. The organs of smell and taste in man are distinguished 

 anatomically by their apparent feebleness of development, 

 and physiologically by their much more extended spheres of 

 action. 



b. The human olfactory organ is comparatively limited in 

 extent. The upper wall of the nose — the cribriform plate — is 

 parallel to the horizontal plane of the head ; its direction 

 being indicated by that of the fronto-ethmoidal suture. 



c. The sense of smell in man is apt to be blunted by his 

 habits of life. But although this sense is actually more 

 acute in certain animals for special odours ; no animal 

 apparently possesses an appreciation so extensive of odours 

 in general. 



d. The structural arrangements which subserve the sense 

 of taste are not confined to the tongue, but extend along the 



