ROOTS AND STEMS. 19 



continuation of the stem, as in Fig. 59, it is a tap-root. 

 Tap-roots are often branching, as in Fig. 59, but many 



FIG. 63. 



FIG. 61. 



FIG. 62. 



common plants have smooth tap-roots, as shown in Fig. 

 6 1, which is known as a conical root. 



FIG. 64. 



FIG. 65. 



