256 PLANT-BREEDING 



required for the beginning of the blooming period varying in 

 the different individuals. If this were so, the character would 

 only be of slight value, and, in the main, dependent on ma- 

 nure and culture. But Tedin found that there are a number 

 of types, differing from each other in the age in which they 

 begin to flower, and that each is constant, when propagated 

 from pure seed. Moreover he observed that the early- flower- 

 ing plants are early in ripening their seeds too, while the 

 late-flowering individuals bring their harvest only in the 

 latter part of the season. That tliis would hold good for 

 the first pods, might be expected, but the observation showed 

 that the rule is applicable to the whole harvest. 



Earlincss of ripening often is a most prevailing point in 

 the determination of the cultural worth of a variety. The 

 influence of unfavorable weather, such as often occurs in 

 the latter part of the summer, is thereby eliminated. Heavy 

 rains may bring the necessity of harvesting in a moist con- 

 dition. Warm and damp weather without sunshine may 

 induce the plants to produce a rich fohage consuming the 

 nutriment for the pods and thus deteriorating them. Cold 

 days protract the process of ripening and thus prolong the 

 exposure to insect pests. All kinds of dangers speak in 

 favor of the cultivation of early varieties. 



Such may now be secured by the correlated mark of 

 the place of the first flower on the stem. On the ground of 

 this mark promising plants are selected and isolated in 

 order to determine their worth afterwards, in their own 

 harvest and in that of their progeny. 



Apples and pears may give a second instance. In the 

 first half of the last century the Belgian horticulturist Van 

 Mons discovered the significance of their numerous elemen- 

 tary species and the relation between their fruits and the 

 form and growth of their foliage and branching. Since his 

 time much has been done for the amelioration of these im- 



