THE ROOT, OR DESCENDING AXIS. 



m 



insures a firm hold upon the earth, and brings a large absorbing sur- 

 face in contact with the moist soil. 



28. White clover — an nxial root (with minute tubers). 24, Buttercups — fibrous root*, 

 inaxiaL 25, Erlgonia — root tuberous. 



118. The summit of the root, or that place where the root meets 

 the stem, is called the collum : the remote, opposite extremities, the 

 ends of the fibers, being chiefly active in absorption, are the spongioles. 

 Neither of these terms denote distinct organs, but places only, and ara 

 often convenient. 



119. FiBRiLL^, a Latin term, refers to those minute hairs, (seen only 

 with a lens), which clothe the younger fibers. They arise from the 

 tender epidermis or skin, and perish when that thickens into bark. 

 These coSperate with the fibers in the absorption of fluids. These two 

 organs are the only efficient absorbers of liquid iiouriahment 



120. Transplanting trees. The flbrillae are developed and perish annuany 

 with the leaves, whose servants they are. Few of them remain after the fall of the 

 leaf This fact plainly indicates that the proper time for transplanting trees or shrubs 

 is the late autumn, winter, or early spring, when there are but few tender fibriUae to 

 be injured. 



121. Two MODES OF EOOT-DEVELOPMENT are definitely distinguished, 

 — the axial and the inaxial. 



122. The axial mode is that where the primary, simple radicle, in 

 growing extends itself downwards in a main body more or less branched, 

 continuous with the stem, and forms the permanent root of the plant. 



