Mutations 73 



The ordinary conception had been that new types of 

 plants had been produced by the slow and gradual piling 

 up of small fluctuating variations. The experience with 

 the primroses shows that new types are formed in much 

 less time than it would take by the accumulation of small 

 variations. It is remarkable that so many different new 

 types of forms should have been produced from the same 

 parent and with no intermediates appearing. When 

 (E. lata, which is a pistillate form, was crossed with 

 (E. Lamarkiana, the progeny of the second generation 

 segregated in mendelian proportion to the pure types of 

 the parents, with no intermediates. This same absence 

 of intermediacy is found when the progeny of the in- 

 constant forms return each year to the parent species, 

 Lamarkiana. 



2. New forms spring laterally from the main stem. 



This conception of the origin of new forms differs 

 markedly from the Darwinian idea which assumes that 

 species are slowly converted into others in the same 

 direction and in the same degree. 



In such plants as draba or helianthemum, from which 

 mutations have been known to arise, no center or "main 

 stem" of mutation would have been known if it had not 

 been seen to occur in pedigree-cultures. For instance, 

 if gigas, rubrinervis, and Lamarkiana had been found 

 growing side by side in equal numbers in the wild state, 

 it would have been impossible to tell which type had 

 been the center of fluctuation. Many years of crossing, 

 together with some vicinism which would probably have 

 followed, would have- been necessary to determine this. 

 De Vries says, "According to the current belief the con- 



