SCAELET EUNNER. ROOT. 99. 



ROOT. 



Observations with the Naked Eye. 



Germinate seeds of Phaseolus multiflorus (the Scarlet- 

 Runner) in wet sawdust, or pure vegetable mould, till the 

 primary root has attained a length of six to eight inches. 



Note with the naked eye 



1. The Seed, from which the testa can easily be 

 removed, disclosing 



2. The two fleshy Cotyledons (no endosperm is 

 present) : between these 



3. The Plumule, which develops early as a stem, 

 bearing foliage leaves. 



4. Below the cotyledons a short Hypocotyledonary 

 Stem, not clearly marked off externally, except by 

 colour, from 



5. The Primary root, on the upper part of which 

 are 



6. Numerous secondary, or Lateral roots. These 

 are formed in acropetal order, and are arranged in 

 regular longitudinal rows, usually four in number. On 

 the youngest part of the primary root (i.e. within three 

 inches or more of the apex) no lateral roots are to be seen. 



Observe that particles of the sawdust, &c., adhere to 

 the older parts of the roots, while the younger apical 

 parts come out of the soil quite clean. 



Microscopic Observations. 



Harden the roots in alcohol for two or three days or 

 more. 



I. Cut transverse sections of the primary root at a 

 point nearer the apex than the youngest lateral roots, 



H2 



