FORMATION OP ROOTS BY LEAVES. 



23 



mentioned in the Gardeners' CJironicle oi 1846, p. 43, where an old 

 Apple-tree, blown entirely out of the ground, so that aU its roots were 

 broken off, nevertheless produced roots from the hard trunk, although 

 the accident occurred in summer when the tree was loaded with fruit. 

 The same observer mentions an Episoia bicolor that happened to have 

 one of its leaves injured by an accident, which cut,the midrib and a 

 portion of the leaf on both sides of it. After a certain time the wound 



Fig. IV. — Leaf of Bpiscia bicolor, which had its midrib cui; across by accident, and formed a 

 young plant at the part that had been injured. 



healed, the part next the base of the leaf remaining of the same thickness 

 as before the injury, while the edge of the outer portion gradually 

 thickened, and developed a small bud close to the midrib, from which 

 a number of minute fibrous roots issued, and eventually a stem and 

 leaves, as represented in the accompanying sketch. Por several months 

 the perfect plant continued to exist in this state, with no other nourish- 

 ment thaai what the portion of the leaf on which it grew, and the air 

 of a warm, damp, hothouse afforded it. As the plant increased in size, 

 the old leaf gradually became exhausted, and perished altogether as 

 soon as the young leaves gained the ascendancy and deprived it of the 



