88 MANUAI, OF nature; STUDY. 



The second use of the roots is to fix and hold the 

 plant in the ground, or natural sub-stratum. In 

 most cases the same roots perform both oflBces, as 

 bean roots, corn, ragweed, hogweed, any kind of 

 tree. Corn roots may be an exception, in that after 

 jointing, this plant sends from a lower node a 

 whorl of braces called aerial roots, whose chief ofl&ce 

 is that of guy rope to the top-heavy corn stalk. 



Some plants, such as creeping vines that grow 

 to cover a whole side of a stone or brick church, 

 have two kinds of roots : one kind in the ground to 

 draw nourishment from the soil, the other the 

 clinging roots which attach themselves to the stone 

 wall for support. To prove that these clinging 

 roots do not absorb food supply, cut off the upper 

 part of the vine from its source of supplies in the 

 earth, and that part will soon wither and die. 



To prove that the roots in the earth do not 

 give mechanical support to the stalk, remove the 

 vine from its fastenings in the wall, and that plant 

 will immediately fall to the earth. 



In fleshy roots, such as radish, turnip, parsnip, 

 etc., aside from mechanical and vital suppport to 

 the plant, a third use is required, viz.: that of stor- 

 ing up starch, fat, sugar and other reserve mate- 

 rials to be drawn upon by the plant at another 

 period in life. 



