THE DUCTLESS GLANDS. 415 



the influence of terror, and the tears excited by sorrow or 

 excess of joy. The quality of a secretion may also be 

 affected by the mind ; as in the cases in which, through 

 grief or passion, the secretion of milk is altered, and is 

 sometimes so changed as to produce irritation in the 

 alimentary canal of the child, or even death (Carpenter). 



The secretions of some of the glands seem to bear a 

 certain relation or antagonism to each other, by which an 

 increased activity of one is usually followed by diminished 

 activity of one or more of the others; and a deranged 

 condition of one is apt to entail a disordered state in the 

 others. Such relations appear to exist among the various 

 mucous membranes : and the close relation between the 

 secretion of the kidney and that of the skin is a subject of 

 constant observation. 



CHAPTEE XIII. 



THE YASCULAR GLANDS : OR GLANDS WITHOUT DUCTS. 



THE materials separated from the blood by the ordinary 

 process of secretion by glands, are always discharged from 

 the organ in which they are formed, and either straight- 

 way expelled from the body, or if they are again received 

 into the blood, it is only after they have been altered from 

 their original condition, as in the cases of the saliva and 

 bile. There appears, however, to be a modification of the 

 process of secretion, in which certain materials are ab- 

 stracted from the blood, undergo some change, and are 

 added to the lymph or restored to the blood, without being 

 previously discharged from the secreting organ, or made 

 use of for any secondary purpose. The bodies in which 



