SECT. II. COMPOSITE ORGANS. 



was produced from the stock or from the graft. 

 Accordingly at the end of four or five months after 

 the time of grafting the tree was cut down, and as 

 the season of the flowing of the sap was past, a por- 

 tion of the trunk including the graft was now boiled 

 to make it part more easily with its bark ; in the 

 stripping off of which there was found to be formed 

 under the graft a thin plate of the wood of the Peach, 

 united to the Prune by its sides, but not by its 

 inner surface, although it had been applied to the 

 stock as closely as possible : hence Du Hamel can- From the 

 eluded that the new layer of wood is formed from the 

 bark, and not from the wood of the preceding year. 7 ear - 

 The same experiment was repeated with the same 

 result upon the* Willow and Poplar; when it was 

 also found that if a portion of wood is left on the 

 graft it dies, and the new wood formed by the 

 bark is exterior to it. The above conclusion, there- 

 fore, is perfectly legitimate, which Du Hamel also 

 strengthens by the following experiment : Having 

 detached a cylinder of bark from its trunk, and 

 covered the wood below it with a thin plate of tin- 

 foil, he then replaced the bark as before^ reducing 

 the case to the following dilemma ; if the new layer 

 of wood was formed from the old layer of wood, then 

 it was plain that the new layer would be deposited 

 within the tin-foil ; and if it was formed from the 

 bark, it was also equally plain that it would be de- 

 posited without the tin-foil : the result accordingly 

 was, that a new layer of wood was deposited between 



