GENERAL BIOLOGY. 33 



of adapting from without foreign matter so as to construct it 

 it into steel and brass, and arrange this just when required, it 

 would imitate a living organism ; but this it can not do, nor is 

 its waste chemically different from its component metals ; it 

 does not break up brass and steel into something wholly differ- 

 ent. In one particular it does closely resemble UTing things, 

 in that it gradually deteriorates ; but the degradation of a liv- 

 ing cell is the consequence of an actual change in its compo- 

 nent parts, commonly a fatty degeneration. The one is a real 

 transformation, the other mere wear. 



Had the watch the power to give rise to a new one like itself 

 by any process, especially a process of division of itself into two 

 parts, we should have a parallel with living forms ; but the 

 watch can not even renew its own parts, much less give rise to 

 a second mechanism like itself. Here, then, is a manifest dis- 

 tinction between living and inanimate things. 



Suppose, further, that the watch was so constructed that, 

 after the lapse of a certain time, it underwent a change in its 

 inner machinery and perhaps its outer form, so as to be scarcely 

 recognizable a§ the same ; and that as a resxilt, instead of indi- 

 cating the hours and minutes of a time-reckoning adapted to 

 the inhabitants of our globe, it indicated time in a wholly dif- 

 ferent way ; that after a series of such transformations it fell to 

 pieces — took the original form of the metals from which it was 

 constructed — we should then have in this succession of events a 

 parallel with the development, decline, and death of living or- 

 ganisms. 



In another particular our illustration of a watch may serve 

 a useful purpose. Suppose a watch to exist, the works of which 

 are so concealed as to be quite inaccessible to our vision, so that 

 all we know of it is that it has a mechanism which when in 

 action we can hear, and the result of which we perceive in the 

 movements of the hands on the face ; we should then be in the 

 exact position in reference to the watch that we now are as re- 

 gards the molecular movements of protoplasm. On the latter 

 the entire behavior of living matter depends ; yet it is abso- 

 lutely hidden from us. 



We know, too, that variations must be produced in the 

 mechanism of time-pieces by temperature, moisture, and other 

 influences of the environment, resulting in altered action. The 

 same, as will be shown in later chapters, occurs in protoplasm. 

 This, too, is primarily a molecular effect. If the works of 

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