PLANT BREEDING 99 



onions, etc., the seed supply is well purchased 

 one year in advance so that it may be tested 

 in a small way the year before it is planted 

 for crop returns. If it is not true to type one 

 at least has the satisfaction of knowing it be- 

 fore the whole crop comes on. The best plan 

 is, however, to grow one's own seed whenever 

 possible from carefully selected stock plants. In 

 that way plant breeding can be made to contrib- 

 ute in a very practical way to intensive farming. 



The insurance provided by special devices, 

 such as hotbeds, cold frames, greenhouses, and 

 irrigation, avails the grower little unless the 

 plants he grows are especially adapted to the 

 purpose for which they are intended. 



Plant* for special purposes have not up to 

 the present time been developed to a high de- 

 gree of perfection. It is only among the mar- 

 ket gardeners and florists that plants for special 

 purposes are found. 



Gardeners have varieties of lettuce, cucum- 

 bers, and tomatoes which have been developed 

 to meet the peculiar needs of the artificial 

 environment of the greenhouse and the trade 

 which supports the industry. These crops do 

 not thrive well in the open, but are par excel- 

 lence for greenhouse conditions. The Grand 

 Rapids forcing lettuce is a notable example of 



