106 



LEAF-ARRANGEMENT. 



The leaves of Conifers are generally narrow and 

 needle-like. I would venture to suggest that this 

 may be connected with the absence of the fibro- 

 vascular bundles, which are present in the stems 

 of dicotyledons, such as the Beech, Oak, etc. The 

 leaves of the Scotch Pine are needle-like, 1? inches 

 in length, and TO in diameter. They are arranged 



FIG. 26. BOX. 



in pairs, each pair enclosed at the base in a sheath. 

 One inch of stem bears about fifteen pairs of 

 leaves. Given this number of leaves in such a 

 space, they must evidently be long and narrow. 

 If I am asked why they are longer than those of 

 the Yew, I would suggest that the stem, being 

 thicker, is able to support more weight. In con- 

 firmation of this we may take for comparison the 



