344 CONSERVATIVE ORGANS. [LECT. VII. 



He cut out a ring of bark from the stern of an 

 Apple tree, and another from that of a Crab tree, 

 which were particularly distinguished from each 

 other by the colour of their wood. He then trans- 

 posed these rings, applying and fixing, by means 

 of a firm bandage, the bark of the Crab tree quite 

 round the uncovered part of the stem of the Apple 

 tree, and that of the Apple tree round the stem 

 of the Crab tree. The air was excluded from 

 both by a plaister of bees wax and turpentine, 

 and covered with well-tempered clay. The in^ 

 ner surface of the Crab tree bark had sinuosi- 

 ties that corresponded with elevated parts of the 

 alburnum of the tree from which it was taken, 

 occasioned by the former extension of many 

 branches ; but that of the Apple tree bark was 

 smooth. In a short time a vital union took place 

 between the applied pieces of bark of both trees, 

 and the bark and alburnum of the trees on which 

 they were bound ; and before the end of the ensu- 

 ing autumn "it appeared evident that a layer of 

 " alburnum had been, in every instance, formed 

 " beneath the transposed pieces of bark, which 

 " were then taken off." " Examining," conti- 

 nues Mr. Knight, ".the organization of the albur- 

 " num, which had been generated between the 

 " transposed pieces of bark of the Crab tree, and 

 " which had formed a perfect union with the al- 



