THE AVOCADO 65 



of the fruit, and are often very extensive. W. R. Home, H. S. 

 Fawcett, and others have noted the presence of several fungi 

 in the cracks and the flesh beneath them, but up to the present 

 it is believed that these fungi are secondary, and not the cause 

 of cracking. 



RACES AND VARIETIES 



The avocados cultivated in the United States are classified 

 horticulturally in three races : the West Indian, the Guate- 

 malan, and the Mexican. The West Indian and Guatemalan 

 races, so far as can be judged at present, are two expressions of 

 one botanical species, Persea americana, while the Mexican 

 race represents a distinct species, Persea drymifolia. 



Horticultural varieties of the avocado, when propagated 

 from seed, do not reproduce the parent fruit in every detail. 

 Seedlings from a round green fruit of the West Indian race may 

 produce fruits oblong or pyriform in shape, and red or purple 

 in color, varying from the parent in numerous other ways as 

 well. But these seedlings will always be like their parents in 

 certain respects, because they belong to the same race and will 

 reproduce the racial even though not the individual char- 

 acteristics. 



To use the definition of H. J. Webber, 1 " Races are groups of 

 cultivated plants that have well-marked differentiating char- 

 acters, and propagate true to seed except for simple fluctuating 

 variations." Technically speaking, the Mexican avocados 

 should not be called a race, since they really represent a species ; 

 the West Indian and the Guatemalan, however, do not appear 

 to differ from each other except in minor characters. 



The classification of avocados into these three races has been 

 useful, inasmuch as it brings together all those varieties which 

 have several characteristics in common. In fact, the mere 



1 In the Standard Cyclopedia of Horticulture. 



