526 Bctrospective Criticism. 



single state may be seen every season. An old root of a dahlia allowed to 

 stand on the same piece of ground, without manuring, and to accumulate a 

 number of stems, seldom produces full flowers. Mr. Munro's is an instance 

 in point ; but it is not two kinds of sap, but a more highly organised state, 

 and a crude unelaborated state, of the same sap. When the quantity of sap is 

 great, as in young and vigorous plants, flowers are seldom at all produced, 

 till the process of growing, b)' extending the system of leaves and branches, 

 has produced the proper balance. The plant, which formerly had more sap 

 than its chemical and vital powers could elaborate into the highly organised 

 state required for producing fruit, having now acquired more strength, be- 

 comes fruitful ; and, exhausted by its fruit-bearing, generally continues fertile, 

 unless deluged again with too much food, in the shape of manure. Such 

 plants as fruit-trees in which the fruiting state, or state of maturity, is 

 brought about with difficulty, at a lengthened period of years, are seldom found 

 to produce double flowers. In those plants, however, in which the flowering 

 state is produced annually, double flowers are more frequent. The different 

 parts of the flower also differ as to the state of organisation in the food re- 

 quired to feed them. Calyx, corolla, stamens, and pistils, are only more 

 highly organised states of leaves, or what would have been leaves ; and each, in 

 the order they are mentioned, continues to be more highly organised than the 

 preceding. In the ordinary mature state of the plant, with a sufficiency of 

 properly organised food, the germs of these parts of the flower will be pro- 

 duced in the normal manner ; but if an over-supply of food, or of water to 

 carry the food to the absorbent vessels of the root, should ensue, the con- 

 dition of the food may be altered; from a highly organised condition it may 

 be lowered nearer to the comparatively crude state required for leaves. In this 

 state it is obvious that the germs which would have started in the form of pistils 

 and stamens maj' be lowered, for want of proper food, to the inferior condition 

 of petals, or even of leaves. When the branch is highly gorged with unela- 

 borated sap, the pistil may even again assume the state of a terminal bud, and 

 lead away a young shoot from the centre of the flower, as is often seen to be 

 the case in roses and other flowers. The above appears to be the theory of 

 double flowers most consonant to experience, it matters not whose it may 

 be ; and it agrees with all observation, that luxuriant supply of food is the cause 

 of this monstrosity. It is also apparent, that, the farther we reduce the supply 

 of food, it will be the more easy again to gorge the plant which has been starved, 

 and produce monstrosity. If the seed has an extra vigour of itself, it may 

 produce so large an absorbent system of roots as may enable it, in a rich state 

 of the soil, to gorge the flower and produce monstrosity, from an ordinary 

 state of the plant. It will be found, however, more easy in practice to gorge 

 a stinted plant than to luxuriate the ordinary state of one ; and hence the most 

 successful cultivators of double stocks are those who grow them first in a 

 starved condition, and then luxuriate them in a very rich soil; or stint the plant 

 by keeping the seed for some years, provided it is only strong enough to grow. 

 I have seen seed, kept till it was thought to be too old for growing, pro- 

 duce almost every plant with double flowers ; while the very same seed, a few 

 years before, had rarely a double flower among the lot. This will be 

 found a more easy method than to produce the same effect by extra-vigorous 

 seeds, and is that most adopted in practice. 



" 869. Duration of varieties. " In beds of ranunculus flowers, it is easy 

 to pick out the varieties recently raised from seed, from the older varieties, 

 by the greater vigour of the plant. The older varieties of the dahlia, whether 

 from neglect or decay, are not so vigorous as they were at coming out. It is 

 the case with newly raised seedling carnations, and flowers in general. The 

 Lancashire gooseberries are never found to maintain the weights they had 

 originally, when a few years from seed and the plant at maturity. Seedling 

 potatoes have the leaves much more pulpy and vigorous than the old varieties. 

 It is evident that circumstances will affect these, and that sometimes, from 

 better soil, shelter, manure, &c, the case may be changed, and the older 



