11. LATENT AND SEMI-LATENT CHARACTERS. 



§ 3. EVERSPORTING VARIETIES. 



Before I proceed to deal with the results which have 

 been obtained, in horticulture, with these highly variable 

 varieties it is desirable, in order to clear up the concep- 

 tions involved, to fix our attention on the various stages 

 which may be interpolated between a species and a simple 

 and constant variety derived from it. 



We will start from the fact that the chance appear- 

 ance of an anomaly by no means always opens up the 

 way to the acquisition of a novelty. One example out of 

 many will suffice. Pitchers (Figs. 16, 106, and 109, Vol. 

 L pp. 61, 470, 484) are usually found as quite rare and 

 isolated variations,^ but in some species of plants, such 

 as Magnolia and Tilia, tolerably frequently. But a vari- 

 et}^ as rich in these structures as, for example, TrifoUum 

 pratcnsc quinqucfoUnin is in 4- and 5-merous leaves does 

 not exist, although it would obviously attract attention 

 and pay the trouble of breeding experiments.- 



This shows that an anomaly discovered by chance 

 may be the expression of a latent character which cannot 

 be brought to its full state of development. Besides this 



^ Over de erfelykheid van synfisen, Kruidkundig Jaarhoek, Gent, 

 1895, p. 129. 



^A variety of Piciis rcUgiosa, with all its leaves changed into 

 pitchers, has since been introduced into Europe by Mr. Prain^ the 

 Director of Kew-gardens. (Note of 1910.) 



