ANATOMY AND PHYSIOLOGY. 291 



large — one fourth of an inch in diameter — while frequently 

 they are nearly the size of a mustard seed. The color is also 

 various. That of the liver is a dark red, the pancreas of a 

 pale white or gray, the little gland in the inner angle of the 

 eye pink, and the kidneys a reddish yellow. 



510. Function of Secretion. — The function performed by 

 these vessels is an exceedingly curious, and not easily ex- 

 plained phenomenon. For from the blood are eliminated by 

 the various secretory organs, bile, saliva, perspiration, tears, 

 etc., none of which exist there as suck, but they seem to be 

 formed from the chemical elements in the blood by the glands 

 themselves. 



511. Effect of the Emotions upon the Secretions. — 

 The mental emotions greatly affect the secretions. A person 

 in fear is often covered with a cold perspiration, and in some 

 persons in the same situation the salivary glands cease to act. 

 On the other hand the thought of savory food has been known 

 to cause the saliva to issue in a jet from the sides of the 

 mouth. 



512. Reserve Glands. — Some glands also act only on parti- 

 cular occasions, as in the case of a broken bone, or cut in the 

 flesh, when the appropriate vessels set themselves at work to 

 repair the injury. 



513. Secretion after Death. — Certain secretions are con- 

 tinued for a time after the death of the individual. Thus it 

 has been observed that the hair and nails grow considerably 

 after death, provided the disease was a rapid one. so that the 

 system was not reduced by loss or degeneracy of the blood 

 and nervous system. It is also related that in dissecting the 

 poison apparatus of a rattle-snake, the poison was secreted so 



Give the minute anatomy of the glands. Describe their ducts. Mention their various 

 colors. 510. What is the use of the glands? Do the secretions exist ready formed in the 

 blood? 511. What is the effect of the feelings upon secretion ? Give an example. 512. 

 What is said of reserve glands? 513. What is said of secretions continuing some time 

 after death ? Give an example. 



