THE THEORY OF ORGANIC EVOLUTION. 431 



of simply postulating variability without statisti- 

 cally or otherwise defining it. Life is so abundant 

 and so Protean that biologists tend to draw cheques 

 upon Nature as if they had unlimited credit, and 

 in their impetuosity scarce wait to see whether these 

 are honoured. 



But we are now changing all this. From Heli- 

 goland to California, from Plymouth to ^igg, we 

 have now reports of fundamentally important studies 

 on variation, which are rapidly helping us out of the 

 slough of vagueness in which, to the physicist's con- 

 tempt, biology still flounders. The very title Bio- 

 metrika of a new journal is a sign of the times. 



It is far too soon to sum up recent studies on 

 variation, but a few general results are becoming 

 clear. The tiresome objector who challenges the 

 evolutionist to demonstrate a single case of one 

 species being turned into another, has an undevel- 

 oped "time-sense" (all natural history records em- 

 bracing but a fraction of a tick of the cosmic clock) ; 

 and he is a century behind the times, with an out- 

 look like that of the catastrophic or cataclysmal 

 school of geologists. Whoever expects to find big 

 " Jack-in-the-box " phenomena in nature is sure to 

 be disappointed. What the objector should do is 

 humbly to study some of the recent researches in 

 which the persistent patience of those who can ap- 

 preciate millimetres has shown that variability is 

 even greater than was supposed by Darwin, and is 

 certainly not less among creatures living in a state 

 of nature than among those domesticated or culti- 

 vated forms on which Darwin concentrated his at- 

 tention. And he should at least give as many days 

 as the observers have given years to the study of 

 palaeontological series, like those of Ammonites and 



