THE ROOT. 



[chap. 



present. In gathering the specimen take it up carefully, so 

 that the root may be uninjured. 

 Proceed to examine your plant. 



I. Observe the Root, noting in what respects it difters 

 from the parts which grow above ground. It consists of 

 numerous fibres, or of a principal central root tapering 

 downwards and giving off irregularly many thread-like fibrils. 

 It is destitute of the green colouring of the stem and foliage, 

 being pale, or nearly white : it bears neither buds nor leaves, 

 and from its direction it appears to have avoided the light. 

 If you can find the tip of one of the root-fibres uninjured, 

 cut it off and examine it minutely with 

 your magnifying glass. In case you 

 have not the means of examining it with 

 a high magnifier, you will find Fig. i a 

 sufficiently correct representation of it, 

 divided through the middle and magni- 

 fied many times. 



The point which I want you particu- 

 larly to note is this : — The extremity of 

 f.-.'.^l the fibre is covered by a closely-fitting 

 sheath, protecting the actual growing 

 tion through "^thf'eT poi^t, which is hidden immediately with- 



tremity of a Root-fibre, \^ ^^^ ^^^ ^f ^^e shcath, tO wllich it is 



magnined. — gp, grow- ' 



j/^root-'fib'r/'^' ^^^^^^ ' ^ii'^e^^tly joined. This protecting sheath 

 is being constantly renewed at its inner 

 side by the " growing point ;" so that as the outer layers 

 become worn or withered by forcing a way through the 

 soil and pebbles, they are constantly replaced by inner 

 layers which take their turn, replace them, and then die, to 

 be in like manner replaced by fresh inner layers derived 

 from the " growing point " so long as the root continues to 

 live and to lengthen. 



Fig 



