LUTHER BURBANK 



suited for development of the citrus fruits. The 

 initial investigations through which the hardy 

 orange is developed must be made in a more 

 favorable locality. 



I frequently mentioned my belief that a hardy 

 orange could be developed, however, and it is 

 satisfactory to record that experiments along this 

 line have more recently been undertaken under 

 the patronage of the United States Government. 



The variety known as Citrus trifoliata, a wild 

 form which had never been much cultivated, was 

 known to be exceptionally hardy. This was hy- 

 bridized with the sweet orange in the Government 

 experiments just referred to, and the early results 

 are thought to be very promising. 



"Among the seedlings observed," says Profes- 

 sor E. M. East, "several have proven valuable. 

 They form a new class of citrus fruits and have 

 been called Citranges. Three of these varieties 

 have been named the Rusk, the Willits, and the 

 Morton. The Rusk, which is a hybrid of orange 

 crossed by trifoliata, is a small fruit with a bitter 

 tang like the pomelo. It makes excellent marma- 

 lade and preserves. The Willits, coming from a 

 cross of orange upon trifoliata, is a rough, but thin- 

 skinned fruit, resembling an orange in appearance 

 but a lemon in flavor. It is used as a condiment 

 or for citrangeade. The Morton, coming from the 



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