Appendix E 



457 



EXERCISE 23 



Study of Citrus Hybrids 



Object. (a) To study the possibility of obtaining valuable 

 kinds of citrus fruits by means of hybridization. (6) To study 

 the structure of citrus hybrids as compared with their parents, 

 (c) To study the economic value of these hybrids. 



Materials. Obtain from some of the extreme southern ex- 



