Plant Breeding. 279 



443. The After-Care of Crosses. After the last pol- 

 lination, the blossom should again be inclosed until 

 fecundation is effected, which is indicated by a rapid 

 enlargement of the ovary. The paper sack may then 

 be replaced by one of mosquito netting. This should 

 be securely, but not too tightly, tied about the stem of 

 the pollinated flower, to protect the inclosed fruit or 

 seed-vessel from injury during growth and maturity, 

 as well as to render it conspicuous. A label should be 

 placed within the sack, or tied on with it, giving the 

 name of the variety whence the pollen was secured. It 

 is also desirable to record all the operations and ob- 

 servations relative to the crossing. 



444. The Selection of Crossed Seedlings is a most 

 important operation in producing new varieties by cross- 

 ing. If none of the seedlings of the first generation ex- 

 hibit the desired qualities, those of a succeeding genera- 

 tion may exhibit them. The plants nearest the ideal 

 should be selected, and all the seeds from these pre- 

 served for planting. When the ideal plant is found, 

 it may be readily fixed by means of cuttings or grafts in 

 plants generally propagated in this way. In those 

 propagated by seed, several generations of culture and 

 selection may be necessary before the progeny will 

 uniformly resemble the parent. 



445. Planting with Reference to Chance Crossings. 

 Many valuable varieties have unquestionably arisen from 

 accidental crosses between plants of different varieties 

 that chanced to be growing in proximity. Profiting by 

 this hint, varieties are sometimes planted near together 

 to favor self-crossing, a practice to be encouraged. 



