176 



INTRODUCTION TO BOTANY 



To do successful work in plant breeding, one of the first 

 requisites is trained observation ability to recognize the ap- 

 pearance of any valuable character or group of characters in 

 growing plants. A skilled botanist once found twenty-three 

 kinds of wheat growing in a field where the grain was sup- 

 posed to be all alike. One of these kinds was isolated and 

 became the parent of an excellent variety that has been ex- 

 tensively cultivated for about a century. 

 The Concord grape sprang from a seed- 

 ling of one of the common wild grapes of 

 New England. Its originator failed to get 

 another important new variety from among 

 22,000 seedlings that grew from Concord 

 seeds. One of the most valuable black- 

 berries of the low-growing (dewberry) type, 

 the Lucretia, is a variety found grow- 

 ing wild upon a West Virginia plantation 

 during the Civil War. The well-known 

 Wealthy apple originated as a seedling 

 discovered after ten years of seed planting 

 and the use of much more than a bushel 

 of apple seeds. 



167. The perpetuation of desirable varie- 

 ties. In the case of shrubs or trees which 

 one; thatattherighf, can reaf iil y be grafted or budded (sect. 87), 



a wild one at the end , J 



of the first season's or in plants like the potato, the canna, or 

 the gladiolus, which can be propagated by 

 tubers and bulbs, it is easy to perpetuate 

 any new variety. If it is necessary to reproduce the plant 

 by means of seed, it may be found that the desired variety 

 always "comes true"; that is, reproduces itself with little 

 or no perceptible change, as is the case with the established 

 varieties of the grains (sect. 171). On the other hand, the 

 plants may tend to " run out"; that is, to revert to the aver- 

 age original type from which the selected variations have 

 been developed. Sugar beets are particularly troublesome 



FIG. 154. Effect of 



cultivation on the 



parsnip 



The parsnip at the 

 left is a cultivated 



growth. One eighth 

 natural size 



