376 THE POPULAR SCIENCE MONTHLY 



We owe our modern ideas of such variations mainly to de Vries and to 

 those who have followed in his footsteps. Such sudden changes have 

 been long known and were spoken of by Darwin as saltations — or sports. 

 Darwin knew of cases like the ancon ram, from which a race of short- 

 legged sheep was produced. He knew that totally black or melanistic 

 mutations and albinos arise in many groups suddenly, and transmit their 

 characters. A black-shouldered or japanned peacock has appeared more 

 than once and perpetuated itself without selection. It would be out of 

 place to-day to discuss this absorbing problem. That extreme mutations 

 may at times have been an element of progress in nature few will deny, 

 especially if we exclude such monstrous forms as those the breeder has 

 used in building up domesticated races of animals. 



It is not, however, to these extreme examples of definite variations 

 that I wish especially to draw your attention, but to that group of 

 smaller variations of a similar nature that may at their first appearance 

 fall within the limits of ordinary variability. I now ask you, therefore, 

 to follow me in an attempt to apply this latest discovery to the theory 

 of evolution. 



If we trace the ancestors of any living animal — man, for exam- 

 ple — we discover that his ancestry goes back not as a single line, 

 nor as a converging system of lines, but as a vast branching network. 

 Each man has had 2 parents, 4 grandparents, 8 great-grandparents, 

 16 in the fourth generation, 32 in the fifth, 64 in the sixth, 128 

 in the seventh, 256 in the eighth, 512 in the ninth, 1,024 in the 

 tenth. A few generations further removed we should expect to find 

 that the majority of all the individuals of the species had poured their 

 blood, as we say, into each individual of the future generations. Each 

 of us is the descendant of a large population. The statement is not 

 strictly true, for some lines die out, many lines cross, and caste has 

 narrowed the field, but the statement suffices to show that a species 

 moves along as a horde rather than as the offspring of a few indi- 

 viduals in each generation. The mass serves to keep the species afloat 

 in times of calamity, it may have little else to do directly with its 

 advance. Nevertheless this fundamental fact is too often overlooked in 

 the attempt to explain the origin of new races, varieties and species 

 from single favorable variations. 



For advance we must look to those individuals that contribute some- 

 thing new to the species — it is the superman that will add something 

 to the common level of humanity, but the rest keep the race alive until 

 his advent and then carry his kind forward on an advancing wave. 



If we could count those individuals that are the pioneers of advance, 

 their number might be very small ; in order to survive, they must graft 

 themselves onto the stock. They are the harbingers of the better times 

 to come — the forerunners of progress. 



