238 THE FLORIST AND 



any other time of the year, but then it is solid and stationary, and contains 

 the vital essence of another year's growth, and on the return of warm weather 

 in spring the first degree of heat affects it, which appears in the swelling 

 buds ; and, shortly afterwards we find that in cutting a twig liquefaction has 

 taken place, by the oozing out of the sap at the wounds, which is termed 

 bleeding. 



But we are not to suppose that the whole sap of the tree is already in 

 motion ; for this reason. In this case, heat is the mover and it cannot pene- 

 trate so quickly into the stem as into the small branches, owing to its great- 

 er solidity and thickness. So that extension and liquefaction or vegetation 

 begins first in the extremities and goes on gradually until the whole plant 

 becomes in a state of vegetation. The motion of the sap then becomes very 

 strong and rapid, which bursts the bud, expands the foliage, and forces out 

 new shoots. But if a sudden cold spell should come the leaves and young 

 shoots may be destroyed or injured, but not the branches stem or roots as 

 they are more impenetrable. 



It has been supposed that the sap of evergreens does not become solid and 

 stationary like that of deciduous trees; if it does not it certainly becomes so 

 dense in winter as to put the plants into a partial state of rest, and extension 

 and liquefaction appear as strong in them in spring as it does in many decid- 

 uous trees. It is the composition of the sap which causes some deciduous 

 trees to be earlier clothed with foliage than others, they are more easily 

 affected by heat than others. We observe the first effect of cold in the 

 changed color of the leaves in the fall ; this goes on gradually the leaves 

 drop and in time the whole plant appears in a state of rest. 



But we are not to suppose that the whole tree is matured or in a state of 

 rest as soon as the leaves fall ; the sap is still in motion, maturing the wood, 

 and densely filling the veins with vital essence, which is to give vigor to the 

 growth the coming spring ; it gradually becomes solid and stationary, first 

 in the branches, next in the stem, lastly in the roots. But it is to be ob- 

 served that young trees, shrubbery, vines, &c. go more immediately into a 

 a state of rest after the fall of the leaves, than large trees do, because they 

 are more slender. Indeed, young trees in a nursery may be said to ripen 

 their wood before the fall of the leaves, on account of the little nourish- 

 ment they get from the soil after midsummer, being crowded in so small a 

 space ; but it must be midwinter, before large trees, especially oaks, are 

 fully matured. 



When a plant of any kind becomes partly matured early in the fall by 

 drought and again awakened by heavy rains and warm weather, the vitality 



