THE VEGETATIVE ORGANS OF PLANTS. 247 



parts of the primary roots, e, and of the seoondary roots, 

 n, no longer retain the particles of soil ; the hairs upon 

 them being, in fact, dead and decomposed. The newer 

 parts of the root alone are clothed with active hairs, and 

 to these the soil is firmly attached as before. The next il- 



Fig. 42. 



lustration, fig. 42, exhibits the appearance of root-hairs 

 with adhering particles of earth, ivhen magnified 800 di- 

 ameters — A, root-hairs of wheat-seedling like fig. 40; B, 

 of oat-plant, both from loamy soil. Here is plainly seen 

 the intimate attachment of the soil and root-hairs. The 



Digitized by Microsoft® 



