14 



resisting. If it is wanting in quality it will be useless, 

 as bulk without quality finds no place amongst growers 

 for culinary purposes. It is better that a new variety 

 should tend rather to excessive robustness than to the 

 other direction, as all varieties become weakened in 

 course of time ; if there is not a little superabundant 

 vigour when it is developed it soon becomes too weak 

 in its constitution to be profitable, and has to be with- 

 drawn from cultivation. The time of maturity, and the 

 property of being fit to cook at certain periods of the 

 year, are also important features. The idiosyncrasies 

 of consumers must also be considered, for the demand 

 for particular types is very variable. 



Development of New Varieties. 



Having decided upon the varieties which shall be 

 mated together, it is a very important matter to select 

 the tubers carefully. The best examples should be 

 selected and planted, and again selected for two or 

 three years until the highest type is attained. Having 

 done this they should be planted in a position which 

 will allow them to be kept apart from others during 

 the flowering season. Some varieties, notably those 

 which produce tubers early in the year, are very shy 

 bearers of blossom, and considerable trouble is occa- 

 sioned in obtaining seed from them. The blossoming 

 is much assisted if the tubers are prevented from being 

 formed, as the energies of the plant are then directed 

 towards developing flowers. Some varieties which 

 had never been known to produce blossom have been 



