RELIGION AND SCIENCE 253 



which evolution may be supposed to have taken 

 place — natural selection, Lamarckism, orthogenesis 

 and the rest — biology has concerned herself com- 

 paratively little with the form of the process in it- 

 self. But it is here that evolution becomes of value 

 to us in our present search; for once more we become 

 aware of a direction. Partly from the direct evi- 

 dence of palaeontology, partly from indirect evi- 

 dence, but along many converging lines, we can form 

 an idea of this direction which in broad outlines is 

 unassailable. 



During life's existence on earth — a period to be 

 reckoned in hundreds and probably in thousands of 

 millions of years — there has been an increase in va- 

 rious of its attributes. But just as in the inorganic 

 world electrons and atoms still exist as such side by 

 side with molecules, so also the earlier types of liv- 

 ing matter continue to exist side by side with the 

 later. The increase is not therefore seen uniformly 

 in all forms at once, but is most easily observed by 

 studying the maximtim level attained. Size, for in- 

 stance, is one of these attributes; and whereas to-day 

 all variations are to be found between ultra-micro- 

 scopic disease-germs and vast organisms like whales 

 and elephants, there has been ^ gradual steadying 

 increase (tending to a limit) in the size of the largest 

 organisms existing at any one period. 



If we confine ourselves for the moment to the ma- 

 terial side, we find that the directional change in or- 

 ganic evolution can be reduced to this — to an in- 



