154 



HARDWICKE'S SCIENCE-GOSSIP. 



in this country ? Mr. Macmillan speaks of finding 

 it on the Swiss Alps. 



Ilex Aquifolium (L.). Mr. Leighton observes a yellow 

 berried form, or variety, on the Wrekin, Shropshire. 

 Is this the same as foand in cultivation ? 



Potamogeton pusillus, major. We have herbarium 

 specimens, gathered at Ellesmere, that have com- 

 l^ressed stem and broader leaves. "We unhesitatingly 

 name it major, as found on the continent. 



LIST OF ASSISTING NATURALISTS. 



\Coiiti?med/roiu J>. ill.] 



IRELAND. 



Monkstown, Co. Dublin. Greenwood Pim, M.A., 

 F.L.S. Flowering plants, ferns, fungi. 



ENGLAND. 



London, 171 Fleet Street, Lewis Castle, Botany. 



ON THE ARRANGEMENT AND GROWTH 

 OF BUDS. 



By John Gibbs. 



AS buds are found in the axils of leaves, it may be 

 inferred that whatever be the method of leaf- 

 arrangement would regulate the disposition of buds, 

 and as from these buds the branches grow, the form 

 and habit of a plant would depend on the arrange- 

 ment of its leaves. It is, however, found in practice, 

 that other principles enter into the growth of branches, 

 which is determined by laws different in different 

 plants, but generally constant in each species. 



If the leaf-buds on a stem were developed in the 

 same regular order of succession as is observed in 

 the flower-buds of a stock, wallflower, or antirrhinum, 

 the lowest first and then the next above it, and so on 

 to the top, the buds at the base of a stem, on a level 

 with the ground or below it, would begin to grow 

 before those higher up on the stem, and might be 

 expected to grow more vigorously, the effect of which 

 would be to form a bush, as we see in the currant 

 and gooseberry bushes. Plants in which this mode 

 of growth prevails cannot become trees, though 

 having woody stems. To obtain large and well- 

 grown bushes or shrubs, it is necessary to check the 

 tendency to throw up shoots from the lower part of 

 the stem by destroying buds found there. In the 

 stem of a young plum-tree, which we may suppose 

 as tall as that of a currant-bush, we may see a 

 difference in the following year, when its uppermost 

 buds will grow into vigorous branches, those below 

 them remaining undeveloped. This will continue till 

 the plant shall have become a tree. 



In every sort of plant there is a tendency to de- 

 velope buds from certain parts of the stem, leaving 

 those in other places latent or undeveloped, unless 

 called into activity by special circumstances, as for 

 instance, if the buds which take precedence of them 

 should be destroyed by accident, or by design in 

 pruning. The particular places on a stem from 

 which buds will grow most vigorously are determined 

 by the specific or individual character of the plant. 

 The stem of an elder-tree often grows erect for a few 

 feet, when it curves, forming in its upper part an arc 

 of a circle. About the spot where the stem begins to 

 curve the most vigorous branches grow, also erect or 

 nearly so, increasing the height of the tree in propor- 

 tion to their vigour, and each ending in a curve 

 above. It is on this curve in the upper part of a 

 stem that the branches grow, which in the following 

 year bear flowers and fruit ; leafy branches rising 

 from the upper part of the straight portion of the 

 stem, or the lower part of the curve, and diminishing 

 in vigour as the stem on which they grow inclines to 

 a horizontal position. This habit of curving in the 

 upper part of the stem and branches gives an aspect 

 of rotundity to a well-grown elder-tree, in which it is 

 rather like a gooseberry-bush on a larger scale. A 

 similar habit is observable in some of our wild roses, 

 of which erect shoots rise out of the ground several 

 feet when they curve, forming, if let alone, beautiful 

 arches to be covered with bloom in the following 

 years. The stems are straight for a sufficient length, 

 to serve as stocks whereon to graft superior sorts of 

 roses for standards, the natural curve above being 

 pruned away. 



In many larger trees the tendency to curve does 

 not appear, but the stem grows erect for several 

 years, as in the horse-chestnut-tree ; there, as the 

 leaves are opposite, it is not uncommon to find 

 branches on the opposite sides of a stem equal in size 

 and vigour. In other cases two opposite branches 

 differ according as one of them is more exposed to 

 light than the other, that on the shady side being 

 small, while that on the sunny side is larger. When 

 a tree has attained such a size as to have large 

 branches, which themselves continually branch again, 

 it is evident that many buds would be on the 

 side next the central stem, so that if they were de- 

 veloped equally, with the buds placed externally, they 

 would make a thicket of interlacing branches that 

 would come into contact with each other till the 

 growth were stopped by the limits of the space to be 

 occupied. It is, therefore, well for the figure of the 

 tree that buds on the inner, and, therefore, shady 

 side of a branch, should either not lengthen at all, or 

 only to a very limited extent, while those in lateral, 

 or external places, grow to a considerable size. The 

 flowers being in a terminal panicle, the flowering 

 stem often forms two branches below them, which 

 grow equally. This tendency to regularity of growth, 

 only modified by the degree of light or other external 



