Leaf Variation — Its Extent and Sii;?ii/icance. 53 



banding force and energy in one direction that it may be more 

 advantageously expended in another? The Fall growth of 

 the plant, with its increased leafage, may be able to build up 

 stronger fruit-bearing canes for the succeeding season. The 

 quinquefoliate leaves and fertility in one and the same branch 

 at least, seem, at present, incompatible. It is claimed that the 

 fruiting branches of the Sassafras generally bear but the 

 entire form of leaf. In poor conditions plants retrograde. 

 In fruiting canes, or branches, the conditions for the produc- 

 tion of leaves are not favorable. Their " specialt>' " is the 

 elaboration of fruit, and the leaf force is diminished. The 

 single or retrograde leaf on the fruiting cane approaches the 

 single, simple leaves of the seedling plant (Fig. 13). 



Leaf-variation is but a phase of the universal, onward 

 march of all things. We no longer say "the everlasting 

 mountains," for they rise and sink ; the isles of the sea are 

 born and disappear ; change, change is written upon all that 

 is, but nowhere is it more plainly inscril:)ed than upon the 

 foliage of herb, shrub, or tree. 



Note. — The references are to Plate II. — Ed. 



