Variations and Mutations 285 



Today single tomato berries may weigh a pound. In color they 

 may be red, yellow, or pink, and in shape they may be spherical, 

 plum-shaped, or flattened. They exhibit at least three types 

 of leaves and two types of stems. The characteristics due to 

 mutation are inherited, no matter what the soil and climatic 

 conditions may be. 



Bud mutations. Mutations occur not only among plants 

 grown from seed but also among plants, or plant parts, developed 

 from buds. These are called hud mutations or hud sports. On 

 fruit trees one branch will occasionally produce fruit that is of 

 different quahty from the fruit produced on other branches. If 

 the quality of the fruit is superior, these branches may be used 

 in budding and grafting to preserve the variety. Known bud 

 sports are comparatively rare, but it is estimated that at least 

 several hundred horticultural varieties have originated from 

 them. In this country the improved varieties of seedless or 

 navel oranges have been secured entirely by this method. The 

 Boston fern and its forty or more varieties originated in bud 

 mutations from a wild tropical fern. In the potato and some 

 other plants that are usually propagated vegetatively, bud 

 variations are known to occur ; but they are so difflcult to dis- 

 cover in plants of this kind that they have not been of much 

 practical value. 



