128 STEMS 



Observe trees to note habits of position of branches. 

 Classify them as erect, arching, ascending, horizontal, 

 drooping, sagging, etc. Learn to identify, trees by their 

 leaves and general appearance, by their bark and by their 

 individual habit of growth. Thus the arching habit of the 

 horse-chestnut, the drooping twigs of weeping willow, the 

 erect shoots of Lombardy poplar, and the curious position of 

 pepperidge make them easily recognized in winter when 

 they are destitute of foliage. 



Study the habitat of trees. Which favor moist soil? 

 Which thrive well on rocky hillsides? Which grow along 

 watercourses ? 



Queries. How does the bark of beech trees differ from 

 that of oaks, elms, and maples? What bark peculiarities 

 have the birches, sycamores, cherry, sassafras, hornbeam, 

 and cedar? How does the bark on young branches of 

 willow, osier, birch, and poplar compare in color and texture 

 with older branches of the same trees ? 



How do the shape of the tree and position of branching 

 compare in Lombardy poplar, tulip tree, cypress, spruce, 

 white oak, and pepperidge ? 



113. SAP CIRCULATION 



Object. To find out where the sap circulates in stems. 



Apparatus. Stems of corn and horse-chestnut or any other 

 woody plant freshly cut from the stalk, eosin or any other aniline 

 dye, bottle, and water. 



Method. Repeat the experiment for sap circulation 

 with roots, using the stems instead. Place them in light 

 for half an hour, make sections, and examine them as before. 

 What parts absorb the dye in cornstalk? In the other 

 stem? 



