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1917 ANNUAL REPORT 



is found in Guatemala. There are fruits of smaller size than any of those 

 cultivated in California or Florida, but better cultivation would probably 

 increase the bulk of such fruits eind bring them up to six or eight ounces in 

 weight. It is notable that avocado trees growing in unfavorable situations, 

 where the ground is exceedingly poor and hard and there is a severe strug- 

 gle with surrounding vegetation, usually produce small fruits in which the 

 seed constitutes a large proportion of the entire weight. The smallest 

 variety examined weighed three ounces. In this case, however, the size 

 did not appear to be due to unfavorable cultural conditions, but was an in- 

 herent characteristic. The largest fruits found, — varieties included in our 

 introductions under the names Nimlioh and Tertoh, — weighed about three 

 pounds. The common size is from eight to twelve ounces. Fruits of a 

 pound in weight are also abundant, and there are many which weigh 20 

 ounces, but above this there are comparatively few. 



North American avocado growers have already come to recognize 

 that an avocado need not have a rough skin to be a Guatemalan, though 

 this was at first looked upon as one of the characteristics of the race. Many 

 varieties have rough skins, but many do not. Some are as smooth as the 

 Trapp or other varieties of the West Indian race, yet they are none the 

 less Guatemalan avocados. A rough surface indicates a thick skin, and 

 a smooth surface a comparatively thin skin. No variety was seen in Guate- 

 mala in which the skin was very thick, yet smooth on the surface, and con- 

 versely none was seen in which the skin was thin yet rough on the surface. 



In the past we have probably placed too much emphasis in the United 

 States upon the thick skin of the Guatemalan race. True enough, it is 

 commonly thicker than in any other race of avocados at present cultivated, 

 but there are varieties in Guatemala which are in every other respect typical 

 of the Guatemalan race, yet the skin is no thicker than that of the Trapp. 

 One of the varieties in our collection, the Ishim, has a skin thinner than 

 that of the Trapp, yet it would be foolish to say that this fruit does not 

 belong to the Guatemalan race. Some growers have desired to separate 

 the Guatemalan avocados into two groups, the thick skinned and the "hard- 

 shelled." This is perhaps possible, although there is every intermediate 

 stage between the thickest and the thinnest skinned, so that no distinct line 

 can be drawn separating the two groups. The question is, whether emy- 

 thing will be gained by such a classification, based solely upon one char- 

 acter. One might speak of thin-slchined Guatemalans and thick-skinned 

 Guatemalans, but if we go farther and form two groups in our general 

 classificatory system, we may lose sight of the important racial characteris- 

 tics which are common to the thick skinned and the thin skinned alike. 



It has been suggested that some of the thin-skinned Guatemalans 

 might in reality be crosses between the West Indian and the Guatemalan 

 laces. This must be admitted as a possibility, yet I have seen no trees 

 whose character strongly suggested such a cross. 



In figures, the thickness of the skin varies from a sixteenth to a quar- 

 ter of an inch. In the Alta Verapaz skins of such thickness and brittle- 

 ness are found that it is difficult to open the fruits with a knife. They are 

 usually broken in the hands. It has sometimes been thought that thick- 

 ness of skin was correlated with altitude; that is, the thickest skins should 

 be found at the highest altitudes, because the fruit needs more protection 



