How Domestic Varieties Originate 243 



with perseverance, this plan during three or four successive 

 seasons a distinct and fixed variety can generally be 

 secured." Ernest Walker, then a gardener at New Al- 

 bany, Indiana, is of the opinion that the abnormal charac- 

 ter of sports often intensifies itself if the sport is allowed 

 to remain on the parent plant for a considerable time. 

 He has observed this particularly in coleus, where color 

 sports are frequent. "In these," he says, "the sport 

 begins with a branch which may 

 be taken off and propagated as 

 a new variety. If left on the 

 parent, other parts of the plant 

 are 'apt to show similar varia- 

 tions. Indeed, I think it is not 

 best to be in too great hurry to 

 remove a sporting branch, for its 

 character seems to tend to be- 

 come more fixed if it remains on 

 the plant." 



13. The starting-point once 

 given, all permanent progress lies 

 in continued selection. This, as 

 we have already pointed out, is really the key to the whole 

 matter. In the great number of cases, the operator cannot 

 produce the initial variation which he desires, but, by look- 

 ing carefully among many plants, he may find one which 

 shows an indication of his ideal. This plant must be 

 carefully saved, and all of the seeds sown in a place where 

 crossing with other types cannot take place. Of a hundred 

 seedlings from this plant, perhaps one or two will still 

 further emphasize the character which is sought. These, 



FIG. 61. Brussels sprouts. 



