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The main growth of trees in height and diameter is accomplished 

 during the first few weeks of the growing season. The opening 

 of the buds in the spring or early summer is followed by the rapid 

 elongation of the shoot of the season, and the early expansion of 

 its leaves. There after-growth in length is very much retarded, 

 and finally ceases with the formation of the terminal bud, which 

 is to be unfolded in the following season. This terminal bud is 

 formed long before the summer is over and into it are crowded 

 the nutritive substances which supply the food for its early 

 expansion the following year. Upon the size and vigor of the 

 buds thus formed depends the length of the shoot of the following 

 season, other things being equal. Likewise the size and vitality 

 of the bud are measures, in the main, of the conditions obtaining 

 in the seasons in which they were formed. The greater the 

 supply of moisture, up to the optimum degree, the more favorable 

 the temperature, sunlight, etc., the greater is the reserve force 

 in the buds and consequently the more vigorous are the shoots 

 issuing from them. 



It is improbable that the whole growth of the new leader is 

 at the expense of the food stored in the bud alone. That from 

 other parts also doubtless contributes, but the tendency is to 

 crowd the formative materials toward the extremities of the 

 main shoot and the branch. In the sharing of these materials 

 the main shoot leads and the branches follow in the order of their 

 importance. The principal growth, however is undoubtedly at 

 the expense of the locally stored materials, the substances stored 

 elsewhere having their part to play in the development of the 

 tissues in their immediate proximity. 



An examination of the buds reveals the cells of the leaf rudi- 

 ments and axis densely crowded with a granular material which 

 appears to be proteid, responding to several tests for that sub- 

 stance. This is in line with what is known concerning the nature 

 of reserve materials in trees. The density of the stored substance 

 is greatest in the bud, and much less in the stem outside of the 

 bud. 



It is a matter of no difficulty to determine by external markings 

 the limits of annual growth on the younger portions of the stem 



