502 GENERAL MORPHOLOGY OF PLANTS 



budding as in the peach, by layering as in the case of rasp- 

 berries and blackberries, by offsets as in the case of strawberries, 

 etc., or by root stocks, tubers, bulbs, etc., in the case of many 

 other plants. 



673. Difficulty sometimes encountered in fixing desirable 

 varieties. It sometimes happens as a result of crossing that the 

 resulting hybrids and their progeny are so variable and continue 

 to be so that no desirable type or variety can be fixed. It runs 

 out or changes in each succeeding generation. This is especially 

 the case in certain crosses of squashes, as Bailey has shown. In 

 a cross between a summer yellow crook-neck "and a white bush 

 scallop, a squash of great excellence was obtained which com- 

 bined the merits of summer and winter squashes, attractive in 

 form, habit, size and color. It was a most promising type. The 

 seeds of the finest squash in this plant were saved and planted. 

 Only two or three plants from this seed were almost like the 

 parent, the rest being very different, altogether there being one 

 hundred and ten different kinds " distinct enough to be named 

 and recognized." The flowers of one of these plants were infertile 

 to their own pollen, and as the plants were slightly different, cross 

 pollination was resorted to. A few fruits were developed and the 

 seeds of these were planted the following year. " Not one seed 

 produced a squash like the parent." 



674. Objects in developing new varieties. There are many 

 useful ends toward which the plant breeder works. Some of 

 these have already been mentioned as greater productivity, 

 increase of the desired product as percentage of flour, gluten, 

 oil, starch, etc. ; in fruits, improvement of flavor, color, texture, 

 varieties for home consumption, for keeping or shipping quali- 

 ties, etc. ; in fibers, length, strength, fineness or coarseness. So 

 there is the development of varieties suited to different climates. 



the best extreme, since that possesses the highest standard of the desired 

 quality. Sometimes, however, there may be an undesirable quality which 

 must be gotten rid of or decreased. Selection proceeds then to develop 

 a high standard of extremes in desirable qualities and a low standard of 

 extremes in the undesirable qualities if they cannot be entirely gotten rid of. 



