250 Heredity and Eugenics 



arisen by an accumulative process, giving all the same 

 permanence and strength of character as is found in what 

 are called natural species or characters. 



The same process has been applied to other forms and 

 attributes with identical results, the only limitations being 

 such as are imposed by the physical constitution of the 

 organism itself, or of the part in which the modification is 

 being carried on, so that a character might become after a 

 time decidedly injurious in the economy of the species and 

 therefore come under the operation of natural elimination. 

 This pattern, however, is a neutral character and the only 

 limitation is that imposed by the physical constitution of 

 the part and there is apparently no direction in which the 

 modification must never go. 



In another series derived from the original stock, modifi- 

 cations were carried out in the reverse of this one, producing 

 a stock in which all of the spots were reduced to round simple 

 areas with absolutely no tendency to fusion or breaking up 

 of the spots into many tributary rows. From these experi- 

 ments two points are clearly demonstrated: First, it is 

 shown that a selective process may permanently modify 

 one of the most inflexible of characters, namely, pattern, 

 and this modification may even greatly exceed any of the 

 variations known in the species. This selective process is 

 different from the quantitative accumulation which has 

 been employed by plant and animal breeders. It is not a 

 process of hybridization, but is analogous to the processes 

 which a chemist would use in synthetizing a complex com- 

 pound, adding to it first one thing, then another, subtracting 

 from this a product, then adding to it some more, until the 

 end product is totally different from the original material. 

 It is a process of synthesis and not of accumulation. 



