MORPHOLOGY OF ANGIOSPERMS. 



93 



the apex, and place the plant in a moist chamber, it will be found 

 in the course of one or two days that the marks between i and 5 

 have become much further apart, and that the growth in this 

 region is about three times that between 5 and 10. This experi- 



FiG. 60. Longitudinal section through the tip of the root of Indian com {Zea Mays) 

 showing root-cap: a, outer layer; i, inner layer. — ^After Sachs. 



ment indicates that the growth of the root takes place at or near 

 the apex, this region being known as the point of growth, or point 

 of vegetation (Fig. 60). 



Upon examining the tip of a very young root by means of the 

 microscope, it will be seen that the growing point is protected by 



