NUTRITION. 45 



tation proceeds, are replaced by leaves. When 

 leaf buds are found under ground, and become 

 swollen and large, like the crocus, &c. they are 

 called bulbs or conns (31). In both cases young 

 bulbs are produced in the axils of the scales, and 

 feed on the old bulb. Some of the latter tribe 

 raise themselves out of the earth by a very 

 curious process. " In some Gladioli," says Pro- 

 fessor Lindley, " an old corm produces the new 

 one always at its point ; the latter is then seated 

 on the remains of its parent, and being in like 

 manner devoured by its own offspring, becomes 

 the base of the third generation." Leaf buds 

 are divided into regular and adventitious, the 

 former being always found in the axil of the 

 leaves, none of which, in fact, are ever really 

 without them, though in some cases they are 

 undeveloped; so that the arrangement of the 

 branches of a plant would always be the same as 

 that of its leaves, were it not that the buds are 

 very unequally matured : and this regularity is 

 found to exist in reality through every part of a 

 plant, although from the obliteration of some 

 portions, and the non development of others, it 

 cannot always be traced throughout. " It has 

 been distinctly proved, that while roots are pro- 

 longations of the vertical or woody system, leaf 



