84 SYS'l KMAI JC J'OMOLOCY 



Entoinoloj^ists ;iiul [Aaui ])atli()l(»^ists in any I'l'gion ciiu fur- 

 nish lists oi" varieties showinjj^ (•()iiii)arativt' resistance in ai)i)les 

 to eodlin-nu)tli, the aphids, San -Jose scah', fii"e-l)li*,'ht, ai)ple- 

 scab, eedar-rust, hitter-rot, and erown-^all ; pears show great 

 varietal differences to tlie dreach'd blight or to psylla ; peaches 

 to leaf-curl or brown-rot; plums to black-knot; or grajx^s to 

 j)hylloxera and the mikk'ws. These are l)ut examples which 

 can be extended in these and other fruits. Descriptions of fruits 

 in every text or treatise, whether bulletin, catalogue, horticul- 

 tural magazine, pomology, or even note-book should give this 

 information. 



124. The adaptation of varieties to different environments. — 

 \'arieties of all fiuils dilit'er widely among themselves in adapta- 

 tion to a particular region, soil, or set of conditions. Thus, the 

 the AVinesap, Romanite, and Ben Davis groups of apples are pre- 

 eminently well adapted to southern apple regions ; the Fameuse, 

 Blue Pearmain, and Baldwin groups to New York, New England, 

 and Canada. It is hardly too much to say that every variety 

 of every fruit has an ideal soil, climate, and method of culture. 

 Some varieties of every fruit can be grown under more diverse 

 conditions than others, in which case such adaptability becomes 

 a valuable asset; the Baldwin apple, Bartlett pear, Elberta 

 peach, Montmorency cherry, and Concord grape are examples 

 of varieties of great adaptability to soil, climate, and care and 

 thereby have attained the high place which they hold in the 

 fruit-lists of this continent. So far as possible varietal likes 

 and dislikes of all important environmental conditions must be 

 set down in a description. 



125. Permanency of varieties. — It is a common belief that 

 varieties change for better or worse. It is thought, on the one 

 hand, that varieties may become more desirable, or better 

 adapted to conditions to which they were not at first suited ; or, 

 on the other hand they degenerate through unfavorable varia- 

 tions. As a corollary, some fruit-growers and nurserymen think 

 that they can improve varieties by continuous selection of 

 buds for propagation from trees showing favorable variations. 

 However, the weight of scientific authority is against the theory 

 that varieties propagated from cuttings, grafts or bud do or can 

 be changed through the variations that appear in orchard plants. 



