76 Elementary Species 



neither of tliem conveys a real explanation; 

 their aim is chiefly to support different views as 

 to the causes of variability, and the origin of 

 elementary species at large. 



One opinion, advocated by De CandoUe, Dar- 

 win and others, claims that the varieties owe 

 their origin to the direct influence of cultiva- 

 tion, and that the corresponding forms found 

 in the wild state, are not at all original, but have 

 escaped from cultivation and apparently be- 

 come wild. Of course this possibility cannot 

 be denied, at least in any single instance, but it 

 seems too sweeping an assertion to make for 

 the whole range of observed forms. 



The alternative theory is that of van Mons, 

 the Belgian originator of commercial varieties 

 of apples, who has published his experiments in 

 a large work called ' ' Arbres f ruitiers ou Pomo- 

 nomie beige." Most of the more remarkable ap- 

 ples of the first half of the last century were pro- 

 duced by van Mons, but his greatest merit is 

 not the direct production of a number of good 

 varieties, but the foundation of the method, by 

 which new varieties may be obtained and im- 

 proved. 



According to van Mons, the production of a 

 new variety consists chiefly of two parts. The 

 first is the discovery of a subspecies with new 

 desirable qualities. The second is the trans- 



