FORESTS AND THEIR USES. 15 



fourth bud will be over the first, and the spiral has 

 made one revolution. Now, examine an oak twig in 

 the same manner, and the sixth bud will be found 

 directly over the first ; but to reach this the spiral 

 will make two revolutions instead of one; no bud 

 within one revolution of a spiral occurring just over 

 the starting point. In the same manner a willow 

 twig being examined, it will be seen that the spiral 

 makes three convolutions before a bud is reached 

 which is directly over the first, and the number of 

 buds included in the series is eight. Such an exer- 

 cise will give zest to a winter or early spring walk in 

 a wood, and at the same time become a source of 

 instruction. In order to facilitate the recording of 

 such observations a fractional method is adopted, the 

 number of convolutions of the spiral representing the 

 numerator, the number of buds encountered being 

 the denominator. Thus, the beech is J, the alder J, 

 the oak --, the willow f , &c. The ash and horse- 

 chestnut, and some other trees, have the buds in 

 pairs opposite to each other, and the arrangement is 

 commonly that of the simple alternation of pairs. As 

 a matter of course the leaves of the same trees will 

 follow the same plan, and may be studied in the 

 same manner. 



Although it is difficult to find two leaves on the 

 same tree so exactly alike that they cannot be dis- 

 tinguished from each other, yet the general outline, 

 or contour, will always be found to follow a particular 

 type, the veins will diverge at a given angle, and 

 fallen leaves may, without any great difficulty, be 

 referred, after a little practice, to the kind of tree to 



