THE RAW MATERIALS OF EVOLUTION 101 



of accurate data in regard to the variations that 

 do actually occur. It is a tedious task, but 

 peremptorily necessary, and already it is having 

 its reward. The recording and statistical registra- 

 tion of variations such as we find in the pages 

 of the journal called BiometriJca is rapidly helping 

 us out of the slough of vagueness, in which, to 

 the physicist's contempt, biology is so apt to 

 flounder. Let us try to state some of the general 

 impressions that we get from the post-Darwinian 

 study of variation. 



(1) Variations more Abundant than even 

 Darwin supposed. " Even Darwin himself," as 

 Wallace says, " did not realise how much and 

 how universally wild species vary"; but one of 

 the clear results of much patient work of recent 

 years has been the proof that variations are as 

 marked among creatures living wild in nature 

 as they are among those under man's control. 

 The fountain of change is even more copious 

 than was dreamed of. 



In commenting on the " fallacy of the belief 

 that great variation is much rarer in wild than 

 in domesticated animals," Mr. Bateson notes 

 that " if we examine the variation in the vertebrae 

 of the sloths, in the teeth of the anthropoid 

 apes, in the colour of the dog-whelks (Purpura 

 lapillus), etc., we find a frequency and a range of 

 variation matched only by the most variable of 

 domesticated animals." We get the same im- 

 pression when we look at a good collection of 

 cuckoo's eggs, or of land-snails, or of ruffs, and 

 so on through a long list. 



It is difficult to realise the frequency and amount 

 of variations until one begins to measure and 



