THE PLANT 5 



The cells grow on, and consequently get crushed and 

 injured. The root dies back a little and then branches, 

 and grows again. If the soil becomes either too wet or 

 too dry, the roots at length decay and the plant falls over ; 

 there is no disease, though, if the soil is wet, the plant 

 may rot. 



If the thick cord-like roots are cut through at the tips, 

 it appears to encourage the growth of the thread-like roots ; 

 if they are cut through at some distance from the tip, 

 they burst out at the severed ends into numerous branches 

 of equal thickness, which continue to grow in much the 

 same direction ; the thread-like roots are multiplied by 

 this means also, and in consequence the capacity for 

 absorbing food material from the soil in both cases is 

 increased. 



The roots do not approach the surface nearer than 

 about 2 in. ; but if mulching is applied to the soil, the 

 roots may run into the mulch, or very near the surface, 

 and care must be taken to keep the mulch renewed, other- 

 wise the roots will get burnt off. The depth to which 

 they descend depends on the nature of the soil> modified 

 by deep cultivation and drainage ; under favourable 

 conditions, the horizontal roots will be found at the depth 

 of 2 ft. 6 in. from the surface, and the vertical roots from 

 the base at a depth of 4 ft. 6 in. They grow rapidly when 

 the soil is rich and in good tilth, at a rate of 2 ft. in a 

 month for vigorous roots starting from the bulb. I have 

 traced them to a distance of 17 ft. from the stem, but 

 their length depends on the conditions favourable to 

 extension. 



The evidence afforded by their structure points to the 

 soil best suited to them a deep loam, well drained, but 

 retentive of moisture from containing a large proportion 

 of humus. 



THE STEM 



The underground " bulb " is the true stem of the plant. 

 The trunk, or apparent stem, is not a true stem, but 



