2 00 THE PHYSIOLOGY OY PLANTS 



close as possible to the leading shoots. Now, if the tips of the 

 lowest leaves are removed, the internodes belonging to them 

 remain short, and the eyes will be in proximity to the leading 

 branches. 



Kecently this method of procedure has been adopted in the 

 case of herbaceous plants (Dahlias), and short, bushy plants are 

 said to be produced. 



The fruit-grower is sometimes forced to a partial removal 

 of leaves to ensure a better development of his fruits. In 

 summers with little sunlight, the almost entire removal of the 

 leaves will be beneficial to fruits which have already attained 

 the requisite size but need the ripening effect of the sun. 



A considerable amount of defoliation is often useful in the 

 case of trees growing in a rich damp soil, to accelerate the 

 ripening of the wood. In such soils after a dry summer a wet 

 autumn will often prevent the formation of winter buds, and 

 the shoots will go on growing until December. Such shoots, 

 however, are very delicate, as they have little wood formed, and 

 are liable to be nipped even by moderate frosts. By pinching 

 off the apex of the shoot and removing some of the leaves, the 

 ripening of the wood is considerably accelerated. The removal 

 of the apex of the shoot removes the tissues which attract the 

 greatest amount of water, and the removal of the leaves allows 

 the shoot to receive more light, which is one of the chief factors 

 in ripening the wood. 



We must now also consider those cases in which the foliage 

 has been damaged against our wish by climatic or other dis- 

 turbing influences. In such cases the amount of damage 

 done depends largely on the cause of the injury. The most 

 detrimental are the damages done by cockchafers or caterpillars. 

 This generally takes place when the leaves are still young. 

 The tree has expended the greater part of its reserve sub- 

 stances on the production of foliage, and has as yet received 

 little or nothing from them. Once more it is leafless, and 

 it requires more reserve material for the unfolding of those 

 buds which have remained uninjured. It has now to draw 

 upon the material stored up more deeply in the main stem, 

 for during the first unfolding the shoots and the roots have 

 used up all the material stored up in their vicinity. After the 



