Problem of Food Movement 561 



this crown now being more vigorous and thriving than that of the 

 rooted tree. Splendid results have been attained by Nature's 

 endeavor to heal the wound at the base of the severed trunk. 



The diameter measurements of the severed branch in com- 

 parison with those of the trunk supported by the roots are level 

 with the shoulders of the man standing by the tree (or trees) 

 12.25 inches and 17 inches; and at the first junction 12 and 13 

 inches. So, while in the rooted tree the taper is 4 inches, that 

 of the severed branch is only one-quarter inch. That a reversal 

 of the natural taper has been taking place probably ever since 

 the cut was made is borne out by careful measurements of a 

 photograph of the tree taken 13 years ago from the identical 

 point from which the one here produced was secured (Forest 

 Leaves, vol. 8, p. 1G8), which give the relative diameters at the 

 lower end as 8.5 and 13 inches, and by such other data as can be 

 secured. The tree stands near Mont Alto Furnace in Penn- 

 sylvania. 



Increment cores taken at both the lower and upper ends show 

 that the annual rings are larger at the upper end. 



The important features brought forward by this case are the 

 continual healthy growth of the severed stem below the graft 

 and the more rapid increase at the junction end of the branch 

 than at the severed end. Manifestly the same forces are work- 

 ing here as in the first case, and the cambium layer is alone 

 active in the severed stump, though, as mentioned before, it is 

 not known how long natural feeding from both roots and leaves 

 was going on before the lower end swung free from the mother 

 trunk. Roots, live limbs and leaves being absent, the reason the 

 upper end grows faster must be because that end gets a larger 

 supply of food, the upper end not allowing any more food to 

 pass its doors than is not actually required for its own growth. 



