or Buds are produced in Trees and Woody Shrubs. 425 



different species of trees.* For this reason it is, that on heading 

 down trees, the germs or buds sometimes appear to be disseminat- 

 ed over the whole surface of the stem, and at other times they are 

 generated close by the eyes. 



To prove the accuracy of this view of the mode in which buds 

 are usually produced, let me now direct the reader's attention to 

 an exception. If a Scotch fir tree be headed down so as to de- 

 prive it of its branches, no new buds will be developed on the 

 trunk or stem, but the tree will die. An examination of a young 

 Sihoot of this tree wiU furnish a satisfactory explanation of the cause 

 of this. It will be seen that the buds upon this shoot are princi- 

 pally terminal, and although a few arise laterally, they are uni- 

 formly at a considerable distance from the base of the shoot. The 

 l^eaves, therefore, which constitute the scales of the bud, do not 

 inclose in their axillae any germs or leaf buds whatever, and the 

 whole buds on the shoot which are not destroyed, are, in the 

 course of time, developed either as branches or as flower buds. 

 Thus no primary buds remain to be developed on the stem when 

 t3ie tree is headed down ; and it has -been already shoAvn that no 

 scale buds exist to be protruded here as in other trees. If more 

 were wanting, therefore, to establish the preceding theory of the 

 circumstances under which buds are produced on the stems of trees 

 when cut down, it is furnished by the above exception, (which I be- 

 lieve is not peculiar to the Scotch fir,) demonstrating that, when 

 these given circumstances are wanting, no germs or buds are formed. 



To conclude, it must be remarked, that I have here endeavoured 

 to explain the circumstances of the production of germs or buds in 

 ordinary cases only. It is well known that occasionally buds are 

 produced upon the roots of plants. To this subject I have not 

 yet directed my attention. Permit me to remark, however, that 

 some powerful connection seems to exist betwixt the bud and 

 the root. In making cuttings we aU know that one or more buds 

 must be put under ground to insure the production of roots ; and 

 it is equally well known, that if an apple tree with a burr, or one 

 of the clusters of buds before described, be planted in the ground, 

 in such a manner as that the burr shall be covered vtdth mould, the 

 branch uniformly pushes out roots, and becomes a separate and in- 

 dependent tree. 



Abbey House, Arbroath, 2\st Aug. 1830. 



A paper " On the Origin of Buds," by the Rev. Mr. Keith, will be found in 

 the last (the xvi.) vol. of the Linn. Trans, p. 421, in which he opposes the the- 

 ory of the writer in the Library of Useful Knowledge, in its universal applica- 

 tion. After stating that the opinion of this author has not the merit of origi- 

 nality, having been previously advanced by Ulrs. Ibbetson, by Du Petit Thouars, 

 and even by Duhamel himself, (though he afterwards abandoned it,) Mr. Keith, 



" Vide Keith's Phys. Bot. Vol. I. c. ii. sec. 1. sub-sec. 2. 



