1911.] PUBLIC DOCUMENT — No. 31. 243 



VII. SUMMARY. 

 Some of the more important results of this work may be sum- 

 marized as follows : — 



1. The many variations in apple varieties arise from many 

 causes, which may be grouped as (1) cultural, using the word 

 in a broad sense; (2) soil; and (3) climatic. Of climatic in- 

 fluences, temperature is the most potent. 



2. The life history of the apple may for convenience in dis- 

 cussion be divided into four periods: (1) growth, extending 

 from the blossom to the attainment of full size; (2) ripening, 

 extending to the time of harvest; (3) after ripening, extending 

 to complete edible maturity; and (4) decay, covering the period 

 of physiological breaking down. 



3. The apple of superior table quality is high in sugars, espe- 

 cially sucrose, and low in insoluble solids, indicating a tender 

 flesh and fine texture. The acid is proportionate to sugars; the 

 ratio may vary somewhat to accord with diiferent tastes. Good 

 kitchen apples are wider in ratio of sugars to acid, and the pro- 

 portion of insoluble solids is of little significance. Good ship- 

 ping apples are high in insoluble solids. 



4. In any variety of apples, high development at full ma- 

 turity is marked by the attainment of full normal size for the 

 variety, high color, well spread over the apple, and a high devel- 

 opment of sugars, especially sucrose. 



5. Each variety has a characteristic chemical composition, 

 fairly constant when perfect maturity is attained. Most of 

 the difi"erences found in difl'erent samples of a variety are due 

 to a difference in the stage of development reached. 



6. The fruit of individual trees shows slight differences in 

 si/e, color, form and abundance that are characteristic and not 

 due to environmental conditions. Some of this may be due to 

 bnd variation, but it is believed that most of it is due to the in- 

 terrelation of stock and scion. 



7. Variation in form in the Ben Davis, and probably in 

 other sorts as well, is due principally to the temperature during 

 a period of about two or three weeks following blossoming. The 

 loAvcr the temperature the more elongated the apple. This elon- 



