166 CAUSES OF BARRENNESS, &C. 



ripening- of the wood) in a stationary state, or some 

 preternatural excitement before they can be perfectly 

 developed. Thus it is why luxuriant growing trees 

 are barren ; and this is the cause why a tree deprived 

 of full air and light yields no fruit ; and also the 

 cause why a branch of a fruitful vine, if lowered 

 from its station near the glass down on a trellis near 

 the floor, will grow luxuriantly, but instead of perfect 

 branches yields only naked tendrils. 



The fact, that over free growth retards the produc- 

 tion of flowers and fruit is evident from many cir- 

 cumstances occurring in vegetation. Seeds, from 

 long keeping, or from being immoderately dried, 

 always rise with less vigour, and present the fructifi- 

 cation sooner than such as are fresh and plump. The 

 reason is because the cotyledons are deprived of a 

 part of their juice, which is destined to invigorate 

 the infant plant ; consequently, when sowed, they 

 vegetate slowly and imperfectly ; but the corculum, 

 from its central position, being less debilitated than 

 its investments, progresses before these, and the 

 result is earlier flowering and maturity of fruit. 



If bulbs be exposed to unnatural desiccation, the 

 outer investment becomes parched and stationary ; 

 but from the central store of sap and vitality the 

 flower issues forth before the leaves. Or, in the case 

 of a bulb being injured by frost, the leaves only are 

 paralysed, and the flower stem is protruded alone. 



That the fructification exists, and has form as 

 soon as the other parts of the plant, is manifest from 



