28 _ PHYSIOLOGY AND ANATOMY. 
Secretion means a separation Of fluids. When it is used 
in physiology, it has reference to a certain process by which 
various substances are separated from the blood, without be- 
ing changed in their separation. Without secretion, there ~ 
would be no possible way for the different. parts of the body 
to be nourished. There are three kinds of organs for the 
purpose of secretion: First, the exhalent vessels ; second, 
the follicles ; third, the glands, The head, chest and stomach 
are all lined with a thin covering, which throws out a little 
fiuid, sufficiently to keep them moist and enable them to 
move easily. “ a ee 
The fat, of which I have heretofore spoken, is caused by 
exhalation, or is one form of secretion. It is first an oily, 
- greasy fluid, then becomes hard, and serves as a protection to 
the skin. T oints are lined 
easily. 
_nal exhalations are those which take place out of the body. — 
These are the sweats or perspiration that is continually pass- 
ing off, and a little mist of fluid which passes from the lungs. ° 
_ The second division of sectetory organs is called follicles. 
These are little bags found in the skin near the surface. 
They secrete an oily substance. When this does not pass 
through the pores of the skin, it appears like a little ridge or 
worm ; but if the pores be kept open by frequent bathing, 
_ this fiuid will pass off as soon as it is secreted. There are 
follicles in each ear to secrete the ear-wax, which will produce 
deafness if it be not removed. There is a little follicle at the 
