LIFE 



body of the flame the molecules of the gas are so freely com- 

 bined with the oxygen of the atmosphere that we have a lively 

 combustion. However, the exchange of matter (metabolism) 

 between the outpouring gas and the surrounding air is so reg- 

 ulated that we always find the same molecules in the same 

 quantity at the same spot. Thus we get the permanent flame, 

 with all its characteristics. But if we alter the circulation by 

 lessening the stream of gas, the shape of the flame changes, 

 because now the disposition of the molecules on both sides is 

 different. Thus the study of the gas-jet gives us, even in detail, 

 the features we find in the structure of the cell. 



The scientific soundness of this metaphor is all the more 

 notable as the phrase, "the flame of life," has long been 

 familiar both in poetry and popular parlance. 



In the sense in which science usually employs the 

 word "organism," and in which we employ it here, it is 

 equivalent to "living thing" or "living body." The 

 opposite to it, in the broad sense, is the anorganic or 

 inorganic body. Hence he word "organism" belongs 

 to physiology, and connotes essentially the visible life- 

 activity of the body, its metabolism, nutrition, and 

 reproduction. 



However, in most organisms we find, when we ex- 

 amine their structure closely, that this consists of va- 

 rious parts, and that these parts are put together for the 

 evident purpose of accomplishing the vital functions. 

 We call them organs, and the manner in which they are 

 combined, apparently on a definite plan, is their or- 

 ganization. In this respect, we compare the organism 

 to a machine in which some one has similarly combined 

 a number of (lifeless) parts for a definite purpose, but 

 according to a preconceived and rationally initiated 

 design. 



The familiar comparison of an organism to a machine 

 has given rise to very serious errors in regard to the 

 former, and has, of late, been made the base of false 

 duaHstic principles. The modern "machine-theory of 



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