194 Retrograde Varieties 



long before the day of inspection comes around. 

 Crosses are unavoidable and hybrid seeds will 

 unavoidably come into the harvest. Their 

 number may be limited by an early eradication 

 of the vicinists, or by the elimination of the 

 first ripe seeds before the beginning of the regu- 

 lar harvest, or by other devices. But some 

 degree of impurity will remain under ordinary 

 circmnstances. 



It seems quite superfluous to give more de- 

 tails. In any case in which the selection is not 

 done before the blooming period, some impuri- 

 ties must result. Even if it is done before that 

 time, errors may occur, and among hundreds 

 and thousands of individuals a single anomalous 

 one may escape observation. 



The conclusion is, that flower seeds as they 

 are offered in commerce, are seldom found 

 absolutely pure. Every gardener knows that 

 he will have to weed out aberrant plants, in 

 order to be sure of the purity of his beds. I 

 tested a large number of samples of seeds for 

 purity, bought directly from the best seed- 

 growers. Most of them were found to contain 

 mixtures and wholly pure samples were very 

 rare. 



I will now give some illustrative examples. 

 From seeds of a yellow snapdragon, I got one 

 red-flowered specimen among half a hundred 



