Selection in Agriculture and Horticulture. 77 



of cases of alleged variability in plants whether in the 

 wild or cultivated state suffers a considerable shrinkage 

 so soon as one views the individual statements from the 

 point of view of possible chance crossings.^ 



I maintain, in a word, that much that has up to now 

 been alleged as evidence of variability overstepping the 

 limits of elementary species (that is mutability) should 

 really be attributed to the result of unobserved chance 

 crossings." 



It is worth while to draw attention to the further 

 distinction between agricultural and horticultural selec- 

 tion. For a clear perception of the relations existing 

 between them w^ill facilitate our understanding of the 

 difference between fluctuations and mutations. 



Every year there are put on to the market by pro- 

 fessional gardeners a certain number of so-called novel- 

 ties especially of plants propagated by seeds, for it is 

 these that I have particularly in view.^ They are partly 

 hybrids, partly really new varieties and subspecies, partly 

 species brought from foreign lands. The varieties and 

 subspecies arise suddenly and only a few individuals of 

 them occur as a rule. They seldom appear in the nursery 

 gardens but usually in those of customers, whose total 

 area is of course much greater than that of the firms 

 which supply the seeds, and where as a rule much more 

 time and attention is devoted to the individual plants. 



* See also Hoffmann, Botanische Zcitung, 1881, p. 381. "The 

 seeds of isolated flowering examples have shown no tendency to the 

 formation of variations." 



^ In a later section T propose to deal with this comparison ex- 

 haustively and from the point of view of careful experiment. 



^ The commercial aspect of breeding has been most thoroughly 

 gone into by C. Fruwirth, Ziichtungsbcstrehiingcn in den Vcreinig- 

 icn Staaten, in Fuhling's Landzvirthsch. Zeitung, 1887, Jahrg. s^^ 

 p. 16. 



