CHAPTER XXXII 



VARIATION AND ITS RESULTS 



398. The Fact of Variation. No two plants are alike 

 (16). In size, form, color, weight, vigor, productiveness, 

 season or other characters, they differ. The most usual form 

 of any plant is considered to be its type, that is, its repre- 

 sentative form. Any marked departure from this type is a 

 variation, that is, a difference, 



399. The Kinds of Variations. Variations are of many 

 degrees. The differences, in any case, may be so slight as to 

 pass unnoticed, or they may be so marked as to challenge 

 even the casual observer. If a red-flowered plant were to 

 produce flowers in different shades of red, the variation 

 might not attract attention; but if it were to produce 

 white flowers, the variation would be marked. When- 

 ever the variation is so marked and so constant as to 



be worth naming and describ- 

 ing, it is called a variety in 

 descriptive botany. If the 

 variation is of such charac- 

 ter as to have value for cul- 

 tivation, it is called an agri- 

 cultural or horticultural va- 

 riety. There is no natural 

 line of demarcation between 

 those variations that chance 

 to be named and described 

 as varieties and those that do 

 404. An arborvit* tree, from which seeds not ; Varieties are only named 



were taken one day. Variations. 



(236) 



