16 :©otani5 



ency of the sweet potato in a wild state to form 

 these food masses has been emphasized by careful 

 cultivation. 



Roots are called fibrous when composed entirely 

 of string-like clusters, as, for instance, a bunch of 

 grass or corn roots. 



Fleshy roots are those that thicken and expand, 

 as in the beet, turnip, and carrot. From these 

 thickened parts true roots start forth. Look at a 

 carrot ; the rind or skin of the upper portion of this 

 beautiful golden wedge has, by exposure at the sur- 

 face of the ground, become tough, fibrous, greenish ; 

 it has put forth a cluster of green leaves. The por- 

 tion deeper in the earth has a thin, porous skin, 

 bright golden color, and sends forth root fibres. This 

 carrot is not, then, pure root throughout. The upj^er 

 part of the wedge is stem. Let us carefully lay open 

 the thick top, and cut out one by one the leaf stems. 

 We can now see how they take their rise, and distin- 

 guish the true stem character of the uj^per part of 

 the carrot. The meaning of the long thick wedge is 

 again storehouse — food reservoir. The tendency of 

 tlie carrot to lay up food in this way has been 

 immensely increased by cultivation. Examine a 

 wild carrot, or parsnip, and in the very much smaller 

 " root wedge " we shall detect the true stem charac- 

 ter. A primar}^ root is the first root which starts 



