192 PHYSIOLOGY AND HEALTH. 



449. The outer skin (Fig. XXVI. a, a) or cuticle, covers the 

 body. It is lifeless and insensible. The hangnails of the 

 fingers, the peeling of the iips when we have a cold, are parts 

 of this skin. If we pinch them, we do not feel it. So, also, we 

 may run a pin through this skin at the corners of the fingers 

 or thumb, or trim the thickened skin of the heel, and suffer 

 no pain. It does not ache with the cold nor suffer with the 

 heat. It has no nerves to feel nor blood-vessels to give it life. 



450. The cuticle, sometimes called the scarf-skin, ie 

 formed by, and grows from, the true skin beneath it, and is 

 constantly casting off its surface in the form of powdery scales. 

 But it is as constantly renewed. This process of change 

 never ceases in health. Sometimes this outer layer peels off 

 from the lips in case of a cold, or from the roots of the nails; 

 but soon another takes its place. When it is peeled off, 

 it leaves the true and sensitive skin bare and tender. But, 

 when it is cast off naturally in dead scales, it leaves a layer 

 behind, which protects the more delicate parts beneath. 



451. Over the whole of the child, and on the parts of the 

 Fio. XXVI. Skin and per.spira.tory Apparatus highly magnified. 



a, a, Cuticle. I c, c, c, Perspiratory glands. 



6, 6, True skin. d, d, d, Perspiratory tubes. 



