INTRODUCTION 



WHETHER we realize it or not our interest in trees is due largely to their 

 changes through the yearly cycle. Summer, autumn, winter, spring 

 how the trees differ with the seasons, often changing visibly from day 

 to day and always making the chief element in the great panoramas of the landscape. 

 More than anything else they give the prevailing tone to each succeeding season. 



While these changes seem so sudden a maple covered with leaves yesterday 

 showing but bare branches to-day, a bare twig of apple to-day becoming a bower 

 of blossoming beauty to-morrow they are all carefully provided for long in 

 advance. I once asked a class of high school graduates when the tree buds were 

 formed. "In winter," was the ready reply. And this I judge would have been the 

 answer of the average man on the street. Yet the tree began to develop those buds 

 for next year's growth almost as soon as it began to grow this year. And it kept 

 on with the good work all through the spring and summer, continuing even into 

 autumn until the buds were fully formed, covered with protecting scales, and 

 furnished in twig and trunk and root with sufficient materials for the rapid start 

 into new growth another year. Then only did each leaf send back to the twig its 

 last reserves of food and begin to loosen its hold, taking on beautiful autumnal 

 colors and finally dropping to the ground to disintegrate, and even in death supply- 

 ing to the tree that gave it birth, materials for further growth. 



As a result of these seasonal diversities we can not know even our commonest 

 trees until we have summered and wintered with them, studying them also in the 

 intervening autumn and spring. So the student of trees has always a valid excuse 

 for an excursion out-of-doors a better one than Thoreau's pursuit of last year's 

 birds' nests and if he is sufficiently in earnest to make careful comparisons of the 

 various parts he can always find material to add to his tree herbarium. 



Most people willingly acknowledge the beauty and interest of the trees in 

 the bloom of spring, the foliage of summer, or the glory of autumn, but their interest 

 wanes in winter. Seemingly they are content to think that the trees then are only 



"Bare ruined choirs 

 Where late the sweet birds sang." 



Yet it is true that at no season can one get a better understanding of the 

 trees than in winter. At this time the characteristic features of their growth 

 stand out distinctly. The outlines against the sky, the bark upon the trunks, 

 the manner of branching, the distinctive features of twigs and buds these are 

 best seen in the dormant season when the obscuring leaves have disappeared. 



(v) 



