828 ANNUAL REGISTER, 1805. 



and I wholly remoTcd the bark be- 

 tween the incisions, thus cutting oft 

 all communication through the 

 bark, between the layers and the 

 parent stems. Had the subjo6ts of 

 this experiment now retained their 

 natural position, much new wood 

 and bark would have been formed 

 at the upper lip of the wounds, and 

 none at all at the lower, as I hare 

 ascertained by frequent experiments. 

 The case was now different ; much 

 new bark and wood was ge- 

 nerated on the lower lip of tlie 

 -wounds, become uppermost by the 

 inverted position of the branches ; 

 and I have no doubt but that the 

 new matter, thus deposited, owed 

 its formation to a portion of sap, 

 ■which descended by grayitation, 

 from the leaves growing between the 

 \T0unded parts and the principal 

 stems. 



The result of this experiment ap- 

 pears to point out one of the causes 

 why perpendicular shoots grow with 

 much greater vigour than others : 

 they have, probably, a more perfect 

 and rapid circulation. 



The efl'ects of motion on the cir- 

 culation of the sap, and the conse- 

 quent formation of wood, I was best 

 able to ascertain by the following ex- 

 pedient : — Early in the spring of 

 1801, I selected a number of young 

 seedling apple-trees, whose stems 

 ■were about an inch in diameter, and 

 ■whose height bctAveen the roots and 

 fnst branches, was between six and 

 seven feet. These trees stood about 

 eight feet from each other ; and, of 

 course, a free passage for the w ind 

 to aft on each tree was afl'orded. 

 By means of stakes and bandages 

 of hay, not so tightly bound as to 

 impede the progress of any fluid 

 ■within the trees, I nearly deprived 

 the roots and the lower parts of the 



stems of several trees of all raotiou, 

 to the height of three feet from the 

 ground, leaving the upper parts of 

 the stems and branches in their na- 

 tural state. In the succeeding sum- 

 mer much new wood accumulated 

 in the parts which were kept in mo- 

 tion by the wind, but the lower 

 parts of the stems and roots in- 

 creased very little in size. Remov- 

 ing the bandages from one of these 

 trees in the following winter, I iixed 

 a stake in the ground, about ten 

 feet distant from the tree, on the 

 cast side of it, and ' I attached the 

 tree to the stake, at the height 

 of six feet, by means of a slender 

 pole, about twelve feet long ; thus 

 leaving the tree at liberty to move 

 towards the north and south, or, 

 more properly, in the segment of a 

 circle, of whirh the pole formed a 

 radius, but in no other direction. 

 Thus circumstanced, the diameter 

 of the tree from north to south, in 

 that part of its stem which was 

 most exercised by the wind, ex- 

 ceeded that in the opposite direc- 

 tion, in the following autumn, ia 

 the proportion of thirteen to eleven. 

 These results appear to open an 

 extensive and interesting field to our 

 observation, where we shall find 

 much to admire, in the means which 

 nature employs to adapt the forms 

 of its vegetable productions to every 

 situation in which art or accident 

 may deposit them. If a tree be 

 placed in a high and exposed situa- 

 tion, where it is much kept in mo- 

 tion by M'inds, the new matter 

 which it generates will be deposited 

 chietiy in the roots and lower parts 

 of the trunk ; and the diameter of 

 the latter will diminish rapidly ii\ 

 its ascent. The progress of the as- 

 cending sap will of course be im- 

 peded, and it will thence cause la- 

 teral 



