^62 



FAiiMEftS' REGISTER. 



No. 5' 



bear Iruit of diminished size and flavor. At the 

 same time, the jrrowth becomes less thrifty. By 

 removing a part of the branches, new and vigo- 

 rous shoots are immediately shot ibrth, possessing 

 the same thrifliness of growth, and bearing the 

 same large and fine fruit that are produced from 

 young trees. This is frequently observed to take 

 place spontaneously, where old trees, loaded with 

 Jruit, had been broken down by the wind, and 

 young shoots had subsequently shot up. 



.J. J. T. 



For the Farmers' Register. 

 ESSAY ON VEGETABLE PHYSIOLOGY. 



By George D. Armstrong, Prof, of Nat. Philosophy 

 and Chemistry, in Washington College, Va. 



Chapter IX. 



PRODUCTION AND GROWTH OF BUDS, POINTS 

 OF PRODUCTION. TIME OP PRODUCTION. 

 PROPAGATION OF PLANTS BY MEANS OF 

 BUDS. 



Leaf buds, as they protrude from the stem, have 

 the form of little conical projections ; and when cut 

 across, seem to be of a un.fiirm texture. In this 

 condition thoy must be regarded as gro vving points, 

 consisting of a highly excitable mass of parenchy- 

 matous mutter, originating in, and immediately 

 connected with the pith ; lor although they appear 

 to arise from the bark, yet in reality they are con- 

 nected with the very centre of the stem. In exo- 

 gens they always arise either from the termination 

 ol'the pith, or else from the outer end of one of the 

 medullary rays. In cndogens their origin has not 

 been traced with the same exactness ; but there 

 seems to he no reason to doubt that they arise 

 from the pulpy substance which, in these plants, 

 corresponds to the medullary system of exogens. 

 The formation and growth of a bud is thus describ- 

 ed by Lindley : "Before organization commences 

 in the germ, the embryo branch is an insulated ves- 

 icle, connected with the parent stem merely by 

 cellular matter. The effect of the organic power 

 is the addition of new matter to this living vesicle, 

 or punctum saliens. and the evolution of new parts, 

 till gradually extending in the direction of its axis, 

 it unites with and becomes a part of the parent 

 plant. In the germ thus situated and supplied 

 with nutriment by the cellular tissue surrounding 

 it, the organization of the branch commences as 

 from a centre. The first part which can be dis- 

 tinctly recognized is the pith; surrounding this, 

 we next perceive lines which are the first traces 

 of the spiral vessels of the future branch, running; 

 in a direction from the centre of the parent branch 

 to the peak of the germ ; indications of the sepa- 

 ration of the cellular matter into scales are next 

 perceptible ; but the whole bud or germ is still a 

 truly insulated body, and continues so until cir- 

 cumstances favorable to its complete evolution oc- 

 cur, howev'er distant from its formation. No de- 

 terminate period, therefore, is fixed for the protru- 

 sion of the germ into a bud ; but at whatever time 

 this may happen, its course is traceable from the 

 medullary sheath surrounding the pith, to the sur- 

 face on which it appears, by a pale streak of 

 parenchymatous matter, traversing each annual, 

 concentric, ligneous layer. But this parenchyma- 

 tous track only marks the advancement of the vi- 



tal speck or germ to the surface of each annual 

 belt of wood ; and is altogether useless as far as 

 regards the germ, except in the bell on the surface 

 of^vhich that germ is seated, with the life of which, 

 indeed, its vitality is intimately connected. De- 

 stroy this, and the germ becomes extinct ; aug- 

 ment its vital energy, and the germ is unfolded 

 into a perfect bud and branch ; but leave things aa 

 they are, and the germ will advance to the surface 

 of the next year's belt of wood, and so on pro- 

 gressively, until it be ultimately unfolded, or perish 

 with the destruction of the tree. The twig, there- 

 fore, which appears on the surface of an old hol- 

 low trunk, is still to be regarded as having origi- 

 nated in the first year of the growth of that part 

 of the trunk, however old it may now be; and its 

 progress is traceable through the shell of the v/ood 

 which still remains free from decay."' 



"It is a curious fact, worthy of remark, that the 

 oerm, if not yet unfolded, will not advance through 

 1 any belt of wood, not actually belonging to the 

 'stem on which it originated, however intiniEitely 

 connected with it that belt may be ; and that the 

 specific action necessary for per|)etuating the germ, 

 cannot be begun in any one of a succession of con- 

 centric belts, when it has not originated in the first 

 of the succession." Where two branches have 

 o-rown together, a bud originating in one, can 

 never protrude through a layer of the other, no 

 matter how intimately the two may have become 

 united. "When a bud protrudes to form a branch, 

 the perpendicular vessels of the part on which it 

 appears, separate to permit it to pass between 

 them, and afterwards meet again and pursue their 

 original direction ; a circumstance which seems to 

 determine that buds, although attached to the pa- 

 rent stem, are truly distinct mdividuals ; the lat- 

 eral or vivaperous progeny of the stem, or of the 

 branch on which they grow." If it be true, as 

 Loudon remarks in his 'Encyclopoedia of Agricul- 

 ture,' that in attempting to improve by cultivation, 

 we must imitate nature exactly, or at least, must 

 operate in those ways only of which nature fur- 

 nishes an example, in the natural growth of a 

 bud we see our authority for artificial budding. In 

 placing the bud of one tree beneath the bark of 

 another, and in such a way that its axis comes in 

 contact with one of the medullary rays of that 

 stem, we are but imitating the example set us, in 

 the natural growth of every bud. 



Buds appear at the axils of the leaves only, ge- 

 nerally one to each leaf, sometimes however, as in 

 the peach, we may notice several springing from 

 the same point ; formed in such positions they are 

 protected by the shade of the leaves from the hot 

 sunshine of August and September, which other- 

 wise might destroy bodies so delicately organized 

 as they are when first formed. If one of these buda 

 be carefully dissected and examined, the rudiments 

 of all the leaves which were to have been developed 

 during the next summer,may be discovered careful- 

 ly and' closely packed together. "Nothing can be 

 more curious than the manner in which these lit- 

 tle rudiments of leaves are packed away within 

 the bud, so as to occupy the smallest possible 

 quantity of room ; or more remarkable than the 

 exactness with which the particular mode of fold- 

 ing, which may be peculiar to a given species, is 

 observed in every bud of every individual plant of 

 that species. There is no uncertainty in the dis- 

 position of these minute parts, no confusion in the 



