110 SPECIAL HISTOLOGY. 



female breast (— to ^"), upon the scrotum, and at the base of 

 the penis (^ to ~"). In most other situations their length is 

 from ± to 5 V". The longest, ~ to ~", exist on the surface of 

 the palm of the hand, sole of the foot, and the nipple, where 

 they are generally of the compound kind ; further, the anterior 

 and posterior extremities of the bed of the nail (— to i'"), and 

 the labia minora (i to i'"). The breadth at the base in most 

 of the papillse about equals, or is somewhat less than, the 

 length ; in a few, as in those of the scrotum, prepuce, and 

 root of the penis, it even exceeds the length by I or more, 

 whence these papillae exactly resemble warts, or even short 

 ridges; in the longest papilla?, lastly, the breadth is i to \ 

 the length. 



The thickness of the corium varies from \ to U", and in 

 most places is about \ to §'". It is thinnest (| to |"') in the 

 meatus auditorius externus, in the eyelids, the red border of the 

 lip, the glans penis and clitoridis ; and thickest \ to 1'" on the 

 back, chin, upper and lower lip (the hairy part), the alee nasi, 

 upon the ball of the sole, the extremity of the great toe, the 

 scapula and the nates ; on the heel, 1 to li'". 



The principal chemical characters of the corium agree with 

 those of the connective tissue, of which it is principally consti- 

 tuted. It putrefies with difficulty, and not at all when tanned; 

 it may be easily dried, and then becomes yellowish, trans- 

 parent, and hard, but flexible and no longer subject to putre- 

 faction. In boiling water, it at first shrinks, eventually how- 

 ever dissolving, but not with equal facility in all animals, and 

 in the young, more quickly than in the old, into gelatine, colla; 

 and the same change is effected at the ordinary temperatures, 

 when it is treated with dilute acids and alkalies. 



§ 34. 



The corium is principally composed of connective and elastic 

 tissue, containing in addition, smooth muscles, fat-cells, blood- 

 vessels, nerves, and lymphatics, in great abundance. 



The connective tissue consists of the ordinary bundles, 

 which are in part united into a network, as in the subcutaneous 

 cellular tissue ; in part into larger secondary bundles, trabecule 

 and lamina, which, in the panniculus adiposus, circumscribe 

 larger and smaller spaces filled with fat ; whilst in the fascia 



