54 CIJMPSES IXTO PLAXT-IJFE 



perfectly flat layer of fine fibrous rootlets no 

 thicker than a sheet of paper ; these would doubt- 

 less suck up abundant moisture whenexcr the rain 

 beat upon the rocks, and there, pressed closel)' 

 between the two ja\'ers of stone the plant has its 

 water-suppl\- stored up, and is enabled to look 

 fresh and green when other \e14etation is suffering;" 

 from drought. 



In plant-life there is a marvellous variet}' in 

 root-structure. Roots differ much, not onl)' in 

 form, but in texture and duration of life, so that to 

 gain a true knowledge of them we must carefull}' 

 examine those of herbs, shrubs, and trees, and 

 observation will soon teach us the fact that there 

 exists a close correlation between the form and 

 texture of the root and the si/.c and character of 

 the plant. 'l~he external shape will depend princi- 

 pall)- upon whether a tap-root is developed or no. 

 Such, for instance, as the carrot and the dock are 

 those of the true tap-root character. Of branching 

 roots we may find endless modifications amongst 

 ordinar}' field or garden flowers from the fibrous 

 roots of the little groundsel to the large flesh)- 

 tubers of the dahlia. Between these two types 



