266 THE HUMAN BODY. 



solution causes the rearrangement into carbon dioxide, 

 alcohol, glycerine and succinic acid, of many atoms of car- 

 bon, hydrogen and oxygen which previously existed as sugar; 

 and which during the metamorphosis were probably not 

 passed through the living cell. How the latter acts we do 

 not know with certainty, but most likely by picking certain 

 atoms out of the sugar molecule, and leaving the rest to 

 fall down into simpler compounds. On the other hand, we 

 find cells forming and storing up in themselves large quan- 

 tities of substances, which they afterwards liberate; starch, 

 for instance, being formed and laid by in many fruit- 

 cells, and afterwards rendered soluble and passed out to 

 nourish the young plant. 



Gland-cells might a priori give rise to the specific ele- 

 ments of secretions in either of these ways and we have to 

 seek in which manner they work. Do they simply act 

 as ferments (however that is) upon the surrounding 

 medium; or do they form the special bodies which charac- 

 terize their secretion, first within their own substance, anfl 

 then liberate them, either disintegrating themselves or 

 not at the same time? At present there is a large and an 

 increasing mass of evidence in favor of the second view. 

 There is, no doubt, some reason to believe that every living 

 cell can act more or less as a ferment upon certain solu- 

 tions should they come into contact with it. Not always, 

 of course, as an alcoholic ferment, though even as regards 

 that one fermentative power it seems very generally pos- 

 sessed by vegetable cells, and there is some evidence that 

 alcohol is normally produced in small amount (and presum- 

 ably by the fermentation of sugar) under the influence of 

 certain of the living tissues of the Human Body. As re- 

 gards distinctively secretory cells, however, the evidence is 

 all the other way, and in many cases we can see the specific 

 element collecting in the gland-cells before it is set free in 

 the secretion. For example, in the oil-glands of the skin 

 (Chap. XXVII.) we find the secreting cells, at first granular, 

 nucleated and protoplasmic, gradually undergoing changes 

 by which their protoplasm disappears and is replaced by 

 oil-droplets, until finally the whole cell falls to bits and its 



