80 NUT GROWING 



a fortnight or more for a new leader bud to start. 

 Apparently the tree had utilized this opportunity for 

 repairing the wound so securely that the tree was 

 quite willing to maintain scions after that time. Tak- 

 ing a hint from this experiment I have since that 

 time found it an advantage to pinch off. the tops of 

 rapidly growing chestnut sprouts before the shoots 

 have reached a foot in length. 



The influence of stock upon scion and vice versa 

 is commonly supposed to be nothing more than a re- 

 lation of host and guest, each retaining its identity 

 as a species. As marked an influence as that of the 

 Royal walnut upon the black walnut stock may per- 

 haps occur without loss of identity on the part of 

 host or guest. On the other hand, a pecan tree nearly 

 one foot in diameter near the ground growing at 

 Morgan City, Louisiana, on the grounds of Mr. 

 B. M. Young, was top-worked with a McCallister 

 hybrid. The McCallister, supposed to be a pecan 

 shellbark hybrid, has a very shaggy bark while the 

 pecan does not have bark of that sort. Grafts were 

 put into this top-worked tree at a height of twelve 

 or fourteen feet. They soon caused the pecan trunk 

 of the tree to become shaggy. This would indicate 

 that hormones manufactured by the top may exert 

 profound influence on the entire trunk and root sys- 

 tem. The name hormone is given to a group of 

 secretions belonging to animal and to vegetable life. 

 They enter the blood or sap currents and travel about 

 in the circulation giving instructions to cells which 

 manufacture another group of secretions, the 



