HETEROPHYLLY. 331 
dependent on a greater or less degree of lobing of the 
margin of the leaf; thus,in the yellow jasmine, almost 
every intermediate stage may be traced from an ovate 
entire leaf to one very deeply and irregularly stalked. 
Broussonettia papyrifera, and Laurus Sassafras, and the 
species of Panaz, may be mentioned as presenting 

Fic. 177.—Syringa persica laciniata, showing polymorphous leaves. 
this condition. Sometimes in the last-named genus, 
as also in Pteridophyllum, every gradation between 
simple and compound leaves may be traced. The 
horse-radish (Cochlearia Armoracia) may also be in- 
stanced as a common illustration of polymorphism in 
