106 The Ottawa Naturalist. [Sept. 



descent rather than that of transmution as appHed by Darwin 

 and his followers. According to this theory it is possible for new 

 forms to arise suddenly without passing through a transitional 

 stage. The theory of DeVries has the support of certain evidence 

 deduced from results gained from experiments with (Enothera 

 Lamarckiana. At least 50,000 plants were cultivated by 

 DeVries in his garden for a number of generations, and out of this 

 number about 800 were found to possess characters distinct from 

 those peculiar to the parent forms. These new fonns, moreover, 

 proved to be constant b}^ breeding true in succeeding generations. 

 The occurrence of these forms under domestication may account 

 for the numerous "elementary species" that are found in nature. 



The theory of DeVries is not new. We have noticed how 

 the idea of the creating of new species by the sudden variation 

 of organisms prevailed among some writers of a comparatively 

 early period. In 1864 Von Kolliker, convinced of the weakness 

 of the natural selection theory, promulgated the theory that new 

 and distinct species are born suddenly by leaps. In 1899, 

 Korschinsky, a Russian botanist, as the result of certain observa- 

 tions and study, formulated the mutation theorv. The publica- 

 tion in 1901 by DeVries of his first book on "Die Mutations- 

 theorie" was the first public recognition of importance which 

 this theory received. DeVries' theory is alternative with 

 that of Darwin's as regards the formation of new species, but 

 as regards the general course of evolution and the great principles 

 which govern it the mutation theory is not in contradiction to the 

 descent theory through natural selection, but is rather supple- 

 mentary to it. 



After considering the main principles which are associated 

 with the various theories we have outlined we are forced to make 

 the following conclusions, viz. : 



(1) That no two plants are exactly alike. 



(2) That while "like begets like" in the main yet there is 

 a constant and continual variation going on within the species. 



(3) That some of these variations are fluctuating and un- 

 stable while others are discontinuous and determinate. 



(4) That artificial selection of desirable fluctuating varia- 

 tions ma}'^ raise the standard above the average of the race at 

 least, although the limitations of this method of selection are 

 recognized. 



(5) That the artificial selection of discontinuous variations 

 may result in the developement of superior new strains. 



(6) That a combination of desirable characters through 

 hybridization may result in the creation of hybrids possessed of 

 special merit. 



