24 BULLETIN 743, U. S. DEPARTMENT OF AGRICULTURE. 



green or turn purple, according to the variety. In all parts of 

 Guatemala these two colors seem to be about equally common. 



Besides the common green and purple, variations of these two 

 colors are often seen. A light yellowish green is not rare, and a 

 bright maroon-purple is sometimes encountered. Very rarely a va- 

 riety is crimson-maroon, and very rarely also one is of such deep 

 purple as to suggest black. 



Seedlings grown in California from a tree producing green-colored 

 fruits have in some instances produced green, in others purple fruits. 

 It appears, therefore, that the color of a variety is not necessarily 

 the same as that of its parent. 



Shin. — While its thickness may vary from a sixteenth to a quarter 

 of an inch, the skin of all Guatemalan avocados is coarsely granular 

 in texture, becoming hard and brittle when it is removed from the 

 fruit and dried. It is always sharply differentiated from the flesh. 

 If the fruit is at the proper stage of ripeness, the skin can usually 

 be peeled from it as from a banana ; in some varieties the skin is so 

 thick, however, that it is not sufficiently pliable to peel. In most 

 cases the skin peels readily if the fruit is fully ripe but still firm, 

 with the flesh the consistency of soft cheese. 



Commonly the skin of Guatemalan avocados is about one-eighth 

 of an inch thick. It is often thicker toward the apical end of the 

 fruit than toward the base, but in some varieties the reverse is the 

 case, and in others it is of about the same thickness throughout. The 

 thickest skin seen was that of an avocado from Santa Cruz, Alta 

 Vera Paz. This skin measured slightly more than a quarter of an 

 inch in thickness. Man}^ of the Vera Paz avocados have thick skins, 

 and as these skins are very brittle and can not easily be cut with a 

 knife the common practice is to open an avocado by breaking it in 

 half. When an attempt is made to cut such fruits, the hard woody 

 shell breaks indiscriminately, and a smooth cut can not be made. 



The thickest skins are not found at the highest altitudes, as has 

 sometimes been thought. Thickness of skin seems to be in no way 

 correlated with elevation. At 7,500 feet there is the same range in 

 thickness as at 4.000 or 5,000 feet. The thickest skin seen in Guate- 

 mala was at an elevation of 4,500 feet. 



Xo sharp distinction can be drawn between the thickest skinned 

 and the thinnest skinned varieties of the Guatemalan race. Each is 

 the extreme of variation in this particular character, and there are 

 all intermediate stages between the two. There are no other char- 

 acters which differentiate the thick skinned and the thin skinned; 

 hence, the}^ must both be considered nothing more than variations of 

 the same race. A classification attempting to consider them as dis- 

 tinct groups is purely artificial. 



