ORIGIN OF SPECIES 145 



large number of individuals with the stamp of a 

 lucky throw. For example, no one would maintain 

 that so complex a mechanism as that of a living or- 

 ganism could suddenly appear by the accidental 

 coming together of the materials of which it is at 

 present composed. This is as inconceivable as that 

 an automobile could develop through the chance 

 meeting of wood, iron, rubber, oil, and gasoline ; or 

 to use Paley's old image, that a watch could be pro- 

 duced by the accidental accumulation of pieces of 

 iron. The parts of the automobile and of the watch 

 have been brought together under the direction of a 

 human agent, but what has brought the parts of the 

 organism together? The implication in this question 

 is that there must have been a directing agent of 

 some sort, since bv chance such a fortuitous com- 

 bination is inconceivable. The statement ignores 

 certain properties of living materials that put the 

 two problems in a different light. These are tlie 

 property of growth by which living matter can in- 

 crease indefinitely in volume; the property of mul- 

 tiplication by which a given sam^^le may duplicate 

 itself without limit; and the possibility of changes 

 in the material that furnish new stable conditions. 

 We may not be able at present to explain fully how 

 growth takes place, but there is nothing in growth, 

 as far as known, that is inconsistent with chemical 

 processes. We may not be able to state in detail how 

 cells divide, but the purely physical character of the 



