40 NATURE TEACHING 



rooted" begonias, the veins of which have first been 

 nicked on the lower side with a penknife. The pot or 

 box should be covered with a sheet of glass, and lightly 

 watered occasionally as found necessary. In the course 

 of a week or two roots will begin to be formed at the cut 

 places, and rough wart-like outgrowths to appear on the 

 upper side. From these small leaves are later formed, 

 and develop into little plants. This method is employed 

 for the propagation of these plants, and is of especial 

 interest in showing that in some plants, at any rate, roots 

 and even complete plants are formed by leaves. 



