THE LIFE -HISTORY OF PLANTS. 



197 



Periodicity of Life.— One thing of great im- 

 portance to determine is the time at which these 

 several operations take place, because the successful 

 treatment of the plant under cultivation must of 

 necessity be regulated by it. 



" There is a time for all things," we are told, and 

 that is true, but its truth does not preclude the 

 possibility of the concurrent action of diiierent 

 things at the same time. A plant in full activity, like 

 any other living thing, is certainly spending and 

 gaining at one and the same time, but unless a proper 

 ratio be observed, its activity declines or becomes 

 deranged. In the spring of the year expendituie 

 is in excess of income, 

 and if there were no re- 

 serve to draw upon, it is 

 easy to imagine what the 

 result would be. Gar- 

 deners attribute the cha- 

 racter of the following 

 season's growth to the 

 " well-ripened " or " ill- 

 ripened wood" of the 

 previous autumn, and 

 though the expression is 

 perhaps open to some 

 technical exception, it 

 nevertheless covers a sub- 

 stantial truth. From this 

 point of view, the ripening 

 of the wood, the mere 

 skeleton of the plant, is not 

 of so much consequence, 

 but rather the formation 

 and storage of food in 

 the inner bark and, to 



some extent, in the young unripened wood. Unless 

 during the summer and autumn a sufficiency of 

 suitable bullion-food — if we may be allowed such an 

 expression — be laid up in the store-places of the plant, 

 the growth will be poor in proportion, because there 

 will be no coins to make it with. This constitutes one 

 difference between annual and perennial plants. 

 The energies of an annual plant are concentrated in 

 the formation of seed ; this effected, there is no 

 other store-house to be filled with bullion, and the 

 individual plant dies, leaving the seed only to 

 continue the race. In a perennial plant the energy 

 and life-work is not solely concentrated on seed- 

 production, but food is stored up in the bark, in the 

 tuber, in the bulb-scale, or elsewhere ; and the indi- 

 vidual plant does not wholly die, but bark or bud, 

 tuber or root-stock, or what not, remains in a 

 relatively quiescent state, to burst forth again into 

 activity at the appointed season. This brings us 

 back to the consideration of the bud as a growing- 



Fig. 22.— T-shaped Cut 

 in the Bark of a 

 Rose to allow of 

 tbe insertion of a 

 Bud. 



point formed in summer or autumn, quiescent 

 through the winter, roused into activity in spring, 

 drawing upon the reserves for its supply, and at first 

 incapable of earning income for itself. 



Individuality of Buds. — An ordinary shrub 

 or tree naturally bears hundreds of such buds, but 

 though thus associated and growing from a common 

 stem, yet each bud has an individuality of its own — 

 an individuality in some cases so strong as to enable 

 it to live and go on its way without the aid of its 

 fellows. An instance of this has already been cited 

 in the case of Eose-budding. If the detached bud 

 were not in a measure 

 self - contained, it could 

 not be transplanted with 

 the successful result that 

 gladdens the Rose-grower. 

 A " cutting " or a " slip," 

 again, is nothing but a 

 portion of the stem or 

 branch bearing one or 

 more buds, which, with 

 the necessary care be- 

 stowed by the gardener, 

 in due time grow into 

 shoots as if they had never 

 been severed from the 

 parent stem. So, too, 

 there are some plants in 

 which the buds become in 

 course of growth naturally 

 detached, and grow into 

 distinct plants. This is the 

 case with the Tiger Lily, 

 whose deciduous buds are 

 fleshy scales of which con- 

 bud till it can 



Fig. 23.— Bud of Rose de- 

 tached, and inserted 

 within the Slit of 

 the Bark, as in bud- 

 ding. 



in fact small bulbs, the 

 tain the food necessary for the youn, 

 shift for itself. 



Another illustration of the independence of indi- 

 vidual buds is shown by the growth of a Vine in a 

 lean-to green-house ; the buds at the upper part of the 

 cane in the warm corner next the top of the house 

 burst into leaf before those at the lower part, because 

 they are subjected to more light, and more especially 

 to greater heat, than those at the bottom. 



So with a Wistaria growing outside, but in which 

 one branch has been allowed to enter the green- 

 house ; the buds outside may be still at rest, while 

 those within are in full leaf and flower. 



In these cases the buds have, stimulated by tli3 

 heat, availed themselves of the resources in the stem, 

 long before other buds, less favourably situated, 

 could do so, and before root-action is set up in the 

 roots growing outside. 



The terminal bud — that one placed at the end of 



