OBSERVATIONS ON INVEKTED GROWTH. 155 



laurels that had struck root by such means, and also finely 

 formed plants of spruce and silver firs may be seen growing near 

 larger trees of the same species : tlie lower branches of the old 

 trees had at some period touched the ground, and the two being 

 friendly lo each other a closer union was formed, the branches 

 struck, root into the eartii, seeking nourishment for tliemselves, 

 and g-rowing with erect heads by the side of their parents. Tiie 

 connection was not altogether dissolved, for there was still a rod 

 between the old and the young' tree. The connection in most 

 cases has the appearance of a witiiered limb ; it is not altogether 

 dead, but its increase in thickness, if any, is extremely small ; 

 however there are exceptions, and as I do not recollect having 

 read much about sucli things in works treating on vegetable phy- 

 siology, a few remarks on the subject may not be uninteresting. 



In a wood, some time ago, I met with a pretty large plant of 

 the AVayfaring tree ( Vihurmim hantand) : many of its yovmg 

 branches were bent considerably all over the plant ; some of the 

 lower branches in their bending touched the ground, and getting 

 entangled among the grass, were kept firm until many of them 

 had struck root, and young plants grew around the old one. 

 Some may be ready to say there is nothing remarkable in all 

 this — such things may be seen daily. Well, it may be so ; but I 

 thought I saw in one of the young plants something different 

 from the others, whereby I might get a lesson that would have 

 been interesting even to men who had advanced far in the study 

 of vegetable physiology. Many experiments and observations 

 have been made to ascertain the motion of the sap in trees by such 

 men as Knight, Duhamel, De Candolle, and others : they did 

 not think it trifling, in order to gain knowledge, to make cuttings 

 of various kinds of plants and put them in, in an inverted posi- 

 tion ; by such simple means they gained useful information. 

 Novv I thought I could see in one of these natural layers some- 

 thing like what these men, among other things, sought for, 

 namely, that " the forms generally assumed by trees in their 

 growth, evinced the compound and contending actions of gravi- 

 tation and of an intrinsic power in the vessels of the bark to 

 give motion to the fluid passing throvgh them." 



The part of the branch of the Wayfaring tree, when it reached 

 the ground, was a few feet from the root of the plant ; a kind 

 of arch was formed between the two extremities ; and a few shoots 

 grew from the point of the branch after it had taken root. 



But what appears to be the most remarkable thing of the 

 whole is, what was formerly the smallest part of the branch, to 

 increase in thickness nearest the ground and taper gradually 

 backwards until it readies a certain point, when the branch again 

 gradually increases in thickness as it approaches its original roots. 



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