LEAF-ARRANGEMENT. 



105 



leaves, and the fraction itself the angular distance 

 (i of 360). 



266. The Cherry cycle. In the Cherry, Apple, 

 Peach, Oak, Willow, etc., neither the third nor the 

 fourth leaf, but the sixth, stands over the first; and 

 in order to reach it the thread makes two turns 

 around the stem. This arrangement is very frequent ; 

 but more or less disguised by the torsions which the 

 axis experiences in process of growth. 



295 



295, 296, 297, Showing the course of the spiral thread and the order of the leaf-succession in the axes of 

 Elm, Alder, and Cherry. 298, Axis of Osage-orange with a/section of the bark peeled, displaying the order 

 of the leaf-scars (cycle %). 



rith a/s 



267. In the Osage-orange, the Holly, and some 

 other plants, the attempt has been .made to find 

 spirals of a higher order. 



268. In the leaves of House-leek and the cones of 

 Pine-trees the number of members is very large. 



269. The common arrangement is represented by 

 a series of fractions, each fraction indicating the pro- 

 portion borne by the angular divergence to the entire 

 circumference. Thus |, for the Cherry, indicates that 

 the angular divergence between successive leaves i 



