136 Plant-Breeding 



pears there is the Kieffer class. In apples, peaches, plums, 

 cherries, and currants, there are no important recognized 

 commercial hybrids. In blackberries there is the black- 

 berry-dewberry class, represented by the Wilson Early and 

 others. Some of the raspberries, as the Philadelphia and 

 Shaffer, are hybrids between the red and black species. 

 Hybrids have been produced between the raspberry and 

 blackberry by two or three persons, but they possess 

 no promise of economic results. It is probable that 

 some of the gooseberries are hybrids. Among all the 

 list of garden vegetables (plants which are propagated 

 by seeds) there is apparently not a single important 

 recorded hybrid ; and the same is true of wheat, unless 

 the Carman wheat-rye varieties become prominent, 

 oats, the grasses, and other farm crops (Fig. 40). But 

 among ornamental plants there are many ; and it is signifi- 

 cant that the most numerous, most marked, and most 

 successful hybrids occur in the plants most carefully 

 cultivated and protected, those, in other words, that are 

 farthest removed from all untoward circumstances and an 

 independent position. This is nowhere so well illustrated 

 as in the case of cultivated orchids, in which hybridization 

 has played no end of freaks, and in which, also, every 

 individual plant is nursed and coddled. 1 With such 

 plants the struggle for existence is reduced to its lowest 

 terms ; for it must be borne in mind that, even in the 

 garden, plants must fight severely for a chance to live, 

 and even then only the very best can persist, or are even 

 allowed to try. 



Consult E. Bohnhof, " Dictionnaire des Orchidees Hybrides," Paris, 

 1905 ; also the recent Sanders lists. 



