Roots 131 



may be mere threads themselves, are covered with 

 milhons of hairs, generally so minute as to be hardly 

 visible without the help of a microscope. 



But here again, as we have seen in various ways 

 before, it is the small, insignificant workers which are 

 of the most importance. It is through the younger, 

 threadlike rootlets, and through these millions of 

 minute hairs, that food is chiefly taken up; and this is 

 why, in moving a plant, the gardener is careful to keep 

 a ball of earth round its roots, that the small, deli- 

 cate rootlets may not be injured, and its food-supply 

 lessened. 



The root-hairs are being constantly produced in 

 fresh millions, for each individual lasts but a few days. 



It is difficult in any degree to realize what length of 

 root a plant possesses, for to do this one must measure 

 not only the main root, or roots, but the branches, 

 rootlets and fibres as well ; and even then, the fringe 

 of hairs will have to be left altogether unreckoned. 



An oat or barley plant, for instance, has roots 

 several feet long ; but when we say several feet, we 

 merely mean that they stretch several feet down- 

 wards through the soil. Their real length, if the 

 many roots are measured end to end, branches and 

 all, is a very different matter. A barley - plant 

 grown in a very small quantity of rich porous soil, 

 was found to have a total length of root of 128 

 feet ! This measurement included the fibres, but not 

 the hairs. In loose soil, such as this, roots can make 

 their way easily ; but in closer soil, growth is more 

 difficult, and so slower, and a plant grown in soil of 

 the latter sort had roots only 80 feet long. On}y 80 

 feet; but both the So feet and the 12S feet were packed 



