7(3 



BOTANY OF THE LIVING PLANT 



tlie growing hair, and the dchcate ceU-wall is hned by a thin fihn of 

 cytoplasm surrounding a central vacuole. A gummy softening ot the 

 wall near the distal end leads to a most intimate connection with any 

 solid particle. The state of the rootdiair in the soil is suggested by 

 Fig. 57. As the water in the soil is held in the form of surface films 



Fig. 5S. 

 Sti'dling of Carpinui Dcliilut,. It - 

 hypocotyl. c— cotylt-iiuiii,. /;u'^iii.uii- 

 root. s!L' = latcral ronts. r — rout-liairs. 

 e— epicotyl. / — ioliagc leaf. Natural 

 size. S. 



F.G. 5U. 

 Lni..ill3aUnii of growth near t'.i thr root-tip 

 ot \'it:ta I'nba. in i. the root-tip ha;; been 

 iiiarlvcd with 10 zones i iirin. apart. In II. 

 the same root after Z2 hours. The lines 

 nearest the tip are now most separated owing 

 to the growth ha\'ing been there most aeti\'e. 

 (.Jitter Sachs.) S. 



covering the several particles, the root can by its hturs tap those films, 

 however thin they may be m a dry soil. It is important further to 

 realise how numerous these root-hairs are. It has been estimated 

 that over two hunrlred of them may be borne on one squtire 

 millimetre of surface of the root of a Pea, while in other plants, for 

 instance the Maize, the number may be still liigher. The effect of 

 this is greatly to increase the possible absorptive surface of the root. 



