THE PHYSICAL LAW OF MATTER 169 



excretory activity, or both, and is, alike at all times, the 

 result of circulatory agency. Moreover, sweat represents 

 one of the final results of the manifold changes to which 

 the nutritive materials supplied to the body are subjected, 



FIG. 6^. SECTION OF THE INTERNAL SAPHENOUS NERVE (HUMAN), MADE 



AFTER BEING STAINED IN OSMIC ACID AND SUBSEQUENTLY HARDENED 



IN ALCOHOL. Drawn as seen under a very low magnifying power. 

 (E. A. S.) 



Ep, epineurium, or general sheath of the nerve, consisting of connective tissue bundles 

 of variable size separated by cleft-like areolae, which appear as a network of 

 clear lines, with here and there fat-cells f f, and blood-vessels z> ; per, funiculus 

 enclosed in its lamellated connective tissue sheath (perineurium) ; end, interior 

 of funiculus. showing the cut ends of the medullated nerve-fibres, which are 

 imbedded in the connective tissue within the funiculus (endoneurium). The fat- 

 cells and the nerve-fibres are darkly stained by the osmic acid, but the connective 

 tissue of the nerve is only slightly stained. 



in their passage from the outer world, to the outer world, and 

 affords one of the best examples of the adaptability of the 

 principles of circulation to the production and elucidation 

 of physiological phenomena, as they are displayed in the 

 life and working of the human body and of all living, 

 or organic, bodies. 



