42 LIFE IN NATUKE. 



We seek, then, the source and laws of the force by 

 which the elements of the living body are placed in 

 these relations to each other, and instead of forming 

 the ordinary chemical compounds, are formed into 

 organic substances. And here we turn to facts. 

 Every one knows that decaying substances are the 

 seats of life. The " mould " that infests the stores of 

 thriftless housekeepers, and the fungi that grow on 

 damp and rotting wood, are instances. These low 

 forms of vegetation live on the decaying matter. 

 Let us consider what takes place in their growth. 

 On the one hand, the wood or other substance, in its 

 decay, is giving out force ; on the other, the develop- 

 ing plants are acted upon by force, and are embody- 

 ing it in their structure. One body is ceasing to be 

 organic, and therein is giving off its force, and 

 in immediate connection with it another body is 

 becoming organic, and therefore is ' receiving force 

 into itself. Can we be misinterpreting these facts in 

 saying that the former process is the cause of the 

 latter ; and that the decay gives out the force which 

 produces the growth ? 



To take an illustration. Conceive two watch- 



