238 SOME SPECIFIC ADVICE 



variable attribute of seedlings, any more than 

 a distinct leader is always an attribute of their 

 tops. Some plants have tap-roots and some do 

 not. They vary in this regard, as they do in 

 stature, form, kind of fruit, or habit of growth. 

 When seedlings first start, they usually have a 

 tap-root, but this tap-root tends to vanish as the 

 root system enlarges and becomes diffuse, in the 

 same way that the leader in the top may be lost. 

 There is no evidence that a tree necessarily 

 thrives better if it has a tap-root (see page 151). 



In the third place, a tap-root does not form 

 merely because the roots are cut long or short, 

 or in one way or another. If it is the habit 

 of a plant to develop a tap-root, it will generally 

 do so, even after its original tap is cut (Fig. 

 115), unless prevented by some peculiarity of soil. 

 It will generally throw down two or even several 

 tap-roots instead of one. It must follow, how- 

 ever, that in short -pruned roots, these new 

 leaders will be very close together and approxi- 

 mately under the main shaft of the tree, and 

 therefore appear to constitute a truer tap-root 

 system than when they arise at some distance to 

 the side of the main shaft ; and it is probable 

 that the centermost ones will tend to be the 

 stronger. 



The gist of the whole matter, so far as the 

 theory is concerned, is that individual instances 

 and the results of certain experiments have been 



