214 THE ORIGIN AND 



lary sheath, the bark, and the liber, in the succulent 

 shoot ; while, yet, the germ itself appears a distinct 

 body. As the bud advances in growth, it gradually 

 assumes somewhat of a pyramidal form ; and the or- 

 ganization of the germ, or new branch and leaves 

 within it, commences. Towards the end of the sum- 

 mer, the lobes begin to appear as opposite scales, 

 from amidst which the apex of the germ, covered by 

 other scales, is observed protruding ; whilst in a lon- 

 gitudinal section placed under the microscope, the 

 rudiments of the new branch can be traced ; for it is 

 now obscurely marked by the deposition of alburnous 

 matter, which being paler and more transparent than 

 the rest of the bud, is seen separating the cellular sub- 

 stance to constitute the future pith from that which 

 is to form the bark. But no spiral vessels are yet 

 perceptible ; the alburnous circle is mere semi-trans- 

 parent matter ; and the pith is distinguishable from the 

 cellular substance in which the germ is formed only 

 by the paler alburnous matter surrounding it. The 

 progress of the organization advances a little in au- 

 tumn; but is not perceptible during winter, and it is 

 not until the following spring that the embryon branch 

 is very conspicuous At this period, in the Lilac, for 

 example, it is seen rising as it were from the medul- 

 lary sheath, in which the spiral vessels seem to origi- 

 nate ; and from whence, passing up, they distribute 

 bundles to each of the leaves, which appear now com- 

 pletely organized, although extremely small and com- 

 pressed within the scales of the bud. As the season 

 advances, the bud lengthens ; and at the moment of 

 its opening, the young branch is seen projecting, cloth- 

 ed with its leaves, which gradually unfolding them- 

 selves, display in their axils the rudiments of future 

 buds, destined to run the same course, and become 

 in turn the parents of another series. 



