292 LUTHER BURBANK 



Morton. The Rusk, which is a hybrid of orange 

 crossed by trifoliata, is a small fruit with a bitter 

 tang like the pomelo, with a turpentine flavor. 

 It is said to make excellent marmalade and 

 preserves. The Willits, coming from a cross of 

 orange upon trifoUata, is a rough, but thin- 

 skinned fruit, resembling an orange in appear- 

 ance but a lemon in flavor. It is used as a con- 

 diment or for citrangeade. The Morton, coming 

 from the same kind of cross as the Willits, is a 

 large, juicy, almost seedless fruit, only slightly 

 more bitter than the sweet orange. It has been 

 remarked that instead of an orange the experi- 

 menters were handed a lemon. 



"Young trees of these three varieties have en- 

 dured a temperature of eight degrees above zero, 

 and it is thought that by the use of these, and of 

 similarly obtained varieties, citrus fruit culture 

 can be extended fully 400 miles north of the 

 present region." 



Doubtless the orange will always remain a 

 relatively tender fruit, for it is an evergreen that 

 has never wandered far from the tropics. But 

 it is equally little to be doubted that it could be 

 made much hardier than any existing race of 

 citrus fruits, and the incentive for the production 

 of such a hardy race is so great that there should 

 be no dearth of experimenters in the field, even 



