THE LIFE -HISTORY OF PLANTS. 



195 



be kept clean by band-weeding, or by tbe old- 

 fasbioned plan of boeing, raking, and rolling, several 

 times a year. Tbougb tbe last involves a consider- 

 able amount of labour, it is not labour lost in kitcben 

 and fruit gardens, in wbicb comparatively loose and 

 frequently scarified walks will prove most favourable 

 to the roots of fruit-trees, busbes, and those of other 

 crops, that often run further and increase and 

 multiply faster under the walks than anywhere else. 



THE LIFE-HISTORY OF PLANTS. 



By Db. Maxwell T. Masteus, F.E.S, 



GROWTH OF BUDS. 



IN considering the seed, it was shown bow, in tbe 

 first instance, before the seedling could in any 

 way shift for itself, it was dependent for its food 

 upon tbe stores laid up beforehand for its use in tbe 

 perisperm or elsewhere. Tbe genial beat of spring 



Fig. 18.— Terminal Bud of Ash, enclosed in Bud-scales. 

 Two side buds of later generation are seen beneath. 



might, indeed set tbe juices in motion, but of what 

 avail would that be were there an empty larder? 

 Provident Nature, however, takes care that this 

 shall not be. Tbe life-work of tbe plant whose 

 course we have to trace largely consists in tbe for- 

 mation and accumulation of reserve supplies for 

 future use. As it was with the seedling, so it is 

 with tbe bud. Apart from the special peculiarities 

 of its origin— a matter to be hereafter alluded to — a 

 seedling has much in common with a bud, struc- 

 turally and functionally. With the exception we 

 have noted, its history is much tbe same. 



IsTature of Buds. — Speaking generally, and for 

 the moment without reference to detail, a bud 

 consists of a central growing point, surrounded by 

 scales, as shown in Figs. 18 — 21, showing the buds of 

 various plants still invested by scales, or in process 

 of growth, during which the scales separate and 

 ultimately become detached. The expression " grow- 

 ing point " is applied more particularly to those 



parts of tbe plant by the increased development oi 

 which tbe plant grows in length. Strictly speaking, 

 it should not be confined exclusively to growth in 

 length, but as no inconvenience arises from the 

 limitation, we need not dispense with what is a con- 

 venient and intelligible symbol. In the seedling 

 plant, as has been already mentioned, two such grow- 

 ing points were specially noticeable, tbe one with a 

 general tendency to grow downwards, to form tbe root, 

 tbe other with a propensity to grow in tbe opposite 

 direction, and to form tbe stem and its subdivisions, 

 the branches. In tbe bud there is, to begin with at 

 least, only one such growing point, and its tendency 

 is to grow upwards. It may be objected that in 

 many cases it grows sideways rather than upwards, 

 but that is an accident of its position not affecting 

 the general truth of the statement. In Fig. 18, for 

 instance, if any accident occurred to the end bud, 

 tbe side ones would probably lengthen into shoots at 



Fig. 19.— TJnexpanded Bud of Horse-Chestnut, 



once, without waiting as they otherwise would do. 

 Wherever the growing point has fair play, and is 

 free to grow as it pleases, it grows more or less veiti- 

 cally upwards. Tbe growing point of a bud, then, 

 is tbe structural equivalent of tbe plumule or rudi- 

 mentary stem of the seedling. 



How Buds are Nourished.— It has been 

 shown whence the plumule derives its food, and we 

 have now to inquire from what source tbe young bud 

 gets its supplies. Obviously the bud-scales, dry and 

 thin as they are, are not likely as a rule to contain 

 much food. They cannot act as foster-mothers to 

 the young bud. Moreover, there are plenty of buds 

 destitute of any scales. Tbe only other available 

 source is the branch from which the buds spring, 

 and here, in fact, we shall find an abundance of 

 food stored up in reserve, just as we did in the 

 perisperm of the seed. Beneath the young rind or 

 the dry scaly bark of a twig, between it and Ibe 

 central woody or pithy matter, there is a store of 



