48 , 



PLANTS AND SUNLIGHT 



cally above the first. This is true, 

 no matter which bud is selected as 

 the starting point. Draw a thread 

 around the stem until the two buds 

 are joined. Set a pin at each bud. 

 Observe that two buds are passed 

 (not counting the last) and that 

 the thread makes one circuit of 

 the stem. Representing the num- 

 ber of buds by a denominator, 

 and the number of circuits by a 

 numerator, we have the fraction 

 %, which expresses the part of the 

 circle which lies between any two 

 buds. That is, the buds are one- 

 half of 360 degrees apart, or 180 

 A nuipie tree on the south side degrees. Looking endwise at the 



of a grove. On the south side c f prn +VIP lpr,Tr PC Qr . C oon tr* Ko 9 

 the leaves hung four weeks Stem, me ICaVCS are 86611 LO D6 &- 



ranked. Note that in the 





n e apple 



shoot (Fig. 81, right), the thread 

 makes two circuits and five buds are passed : two-fifths 

 represents the divergence between the buds. The leaves 

 are 5-ranked. 



78. Rhubarb grown in the dark. The leaf-blades do not develop. 



