ELECTRICITY IN THE PHENOMENA OF ANIMAL LIFE. 449 



wliicli we shall see further on, it at once enters into combination with 

 them. It thus sets free new portions of albuminoid matter from the 

 virtual combination which it had formed with them, and these immedi- 

 ately take advantage of the electricity produced by the oxidation to 

 raise their own electric potential to such a point that they may be able 

 in consequence to take their places in turn in the structural edifice of 

 the cell thus endothermically built up. It is in this way that, quite 

 naturally, the cycle of reactions is established which constitutes the 

 rotation of changes in the living machine. 



The mechanism which we have just explained shows how the chem- 

 ical changes which represent the nutrition of the cell take place in the 

 inmost recesses of the living substance itself, from atom to atom and 

 from molecule to molecule, producing", in place and step by step with 

 their occurrence, the electric energy needed for each ensuing reaction. 



Following out this order of procedure, the cell may be said to with- 

 draw from the surrounding medium the nutrient materials which are 

 adapted to the diflerent parts of its own substance by its proper 

 affinity, which I will call selective electrolytic power, but which is 

 merely the resultant of the previous electrical condition of the con- 

 stituents concerned. The dro^jping- out of the one constituent neces- 

 sardy incites the reeutrance of another precisely similar constituent. 

 Thanks to the continuity of the rotational change going on, eacli 

 particle of the cell i)asses in succession, all other things being equal, 

 through the same phases of condition with that which has preceded it, 

 from the moment of its admission to the substance of the cell up to 

 the moment when it becomes separated from it. Before being intro- 

 duced into the substance of the cell the atom must leave the virtual 

 combination in which it was held. It is precisely the disappearance of 

 the atom which precedes that furnishes to the one which follows it 

 the exact amount of energy required to effect its selective electrolysis 

 or its liberation from the state of virtual combination. Thus we shall 

 have concordance, referring to the possibilities of the case, between 

 what the one lacks in order to leave the medium and enter into the 

 substance of the cell and that which the other provides when it frees 

 itself from the combination in Avhicli it has been held in order to 

 engage itself in one more powerful; and, on the whole, quantitatively 

 speaking, there will be a certain available excess of energy on the 

 latter side. It follows from this that the jwiuts of accretion, howsoever 

 distributed as to position in the protoplasm, always retain their iden- 

 tity both in composition and structure; and, as the same causes every- 

 where bring about the same effects, the whole cell must reproduce 

 itself indefinitely with maintenance of its identity if the nutrient 

 medium remain on its part constant in character and the process of 

 transformation go on. - - - 



The preceding- hasty sketch sufficiently shows, I think, that it is 

 legitimate to compare, as I have done at the outset, the mechanism of 

 SM 04 29 



