EXAMINATION OF 



[CHAP. 



they nearly resemble each other it does not signify which 

 is taken. In gathering the specimen take it up carefully, 

 so that the root may be uninjured. 



Proceed now to examine your buttercup. 

 i. Observe the ROOT, noting in what respects it differs 

 from the parts which grow above ground. It consists of 

 numerous fibres, about the thickness of small whip-cord, 

 tapering at their extremities and giving off irregularly 

 many thread-like fibrils. It is desti- 

 tute of the green colouring of the 

 stem and foliage, being pale or nearly 

 white : it bears neither buds nor 

 leaves, and its branches, from their 

 direction, appear 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 higher magnifier, you will find 

 figure i a sufficiently correct repre- 

 sentation of it, divided through the 

 . Longitudinal middle and magnified many times. 

 fi^ The point which I want you particu- 

 of Buttercup, mag- larly to note is this. The extremity 



point 7/iea g th wi ^ of the fibre is covered by a closely 

 root-fibre.' ' fitting sheath, protecting the actual 



growing point, which is hidden im- 

 mediately within the end of the sheath, to which it is 

 directly joined. This protecting sheath is being con- 

 stantly 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. 



The " growing point," as I call it, you perceive consists 

 of a group of minute thin-walled cells with opaque 

 contents, the arrangement of which in relation to each 

 other, or indeed to the surrounding tissues, can hardly be 



FIG. 



