20 NORMAL HISTOLOGY AND ORGANOGRAPHY. 



its allotropic forms. Very small amounts of sulphur 

 are found in living matter. 



Protoplasm is a restless substance, its granules 

 manifesting a slow ameboid movement, which be- 

 comes accelerated with increased physiological ac- 

 tivity. At the end of a day's labor and toil it is 

 not only exhausted but actually depleted, requiring 

 repair and the replacing of its lost particles, which 

 is accomplished by some marvelous, subtle, intrinsic 

 power so characteristic of living matter. Food is 

 the raw material utilized for this purpose, and it 

 naturally follows that the essential elements of food, 

 whether for plants or animals, must be identical with 

 those found in protoplasm namely, carbon, hydro- 

 gen, oxygen, nitrogen, and some sulphur. This is 

 universally the case, as we find these present in the 

 necessary food products, such as carbohydrates, hy- 

 drocarbons, albuminoids, and proteins. As a mat- 

 ter of fact, the diet of man is largely the protoplasm 

 of some other living organism, animal or vegetable, 

 or both. Huxley, in his lecture on the "Physical 

 Basis of Life," very fittingly outlines this transmu- 

 tation of the elements of protoplasm when he says 

 that in order to replace the ' ' number of grains of 

 protoplasm and other bodily substances wasted in 

 maintaining my vital processes ... I shall prob- 

 ably have recourse to the substance commonly called 

 mutton . . . and the subtle influence to which it 

 will then be subjected will convert the dead proto- 

 plasm into living protoplasm and transubstantiate 

 sheep into man. Nor is this all. If digestion were 

 a thing to be trifled with, I might sup upon lobster 



