TREES 39 



first bud, pass it on to the second bud, twisting it around the stem as needed, 

 and then on up to the third bud, the string would make one spiral turn 

 around the stem and touch two buds to get from the one with which you 

 started to the one just above it. The bud arrangement on such a twig 

 might be represented by the mathematical arrangement i over 2, in which 

 the 2 indicates the number of buds in the cycle and the i the number of 

 turns taken around the stem. In the same way find the "fraction" that 

 indicates the bud arrangement on other twigs with alternate buds. You 

 will find that the fraction series runs: \, ^, f, etc. What do you find is the 

 next fraction in the series? Study the series to discover the relation 

 between the fractions so that you can tell without actually finding the twig 

 what the fifth fraction in the series is. 



Parts of bud. Secure twigs of horse chestnut, lilac, white poplar, or 

 any others that have good-sized buds. Pick a bud to pieces and arrange 

 the parts as they occur in the series. What do you find on the outside of 

 the bud ? what on the inside ? What, then, is a bud ? What really are 

 these protective covers ? Cut a bud open lengthwise and draw a diagram 

 representing the section. Do the same with an onion. Comparing the 

 two, what would you say is the real nature of an onion? How does it 

 differ from a bud ? 



Common trees. Learn to know the following trees both in their sum- 

 mer and in their winter condition. Refer to such books as Blakesley and 

 Jarvis' Trees in Their Winter Condition, Apgar's Trees of North America, 

 Hough's Trees of the United States, Lounsberry's How to Know the Trees. 

 There follows (p. 42) a key that will serve to identify the common trees 

 of this region. 



Acer negundo: box elder 



Acer rubrum: red maple 



Acer platanoides: Norway maple (introduced) 



Acer saccharinum: soft maple 



Acer saccharum: sugar maple 



Aesculus hippocostanum: horse chestnut 



Ailanthus glandulosa: ailanthus 



Alnus vulgaris: European alder 



Betula alba papyrifera: white birch 



Catalpa speciosa: catalpa 



Celtis occidentalis: hackberry 



Cercis canadensis: redbud 



Crataegus Crus-galli: hawthorn 



Fraxinus americana: white ash 



Fraxinus nigra: black ash 



Fraxinus pennsyhanica: red ash 



