40 ANGLE OF INSERTION [CH. V 



upper parts by insects, wind-breakage, &c., the removal 

 of the powerful competitors for food- materials and water 

 enabling the minute dormant buds to make use of the 

 abundant supplies afforded by the powerful roots. 



These cases are distinct from some others where 

 adventitious buds i.e. buds making themselves evident 

 out of their proper order arise on various parts of the 

 stem, or even the root in exceptional cases, and give 

 origin to shoots in quite exceptional places: these matters 

 will be dealt with elsewhere. 



The angle of insertion of the lateral buds on the 

 long shoots differs considerably in different trees, and it 

 commonly differs on one and the same shoot at base and 

 apex. For instance, the buds of Lonicera Xylosteum stand 

 out at nearly a right-angle with the shoot, while those of 

 the Black Poplar and many Willows are erect and practi- 

 cally parallel with the shoot bearing them, or they may 

 even have their tips incurved ; those of the Beech diverge 

 at an angle of about 45, and those of the Hornbeam at a 

 smaller angle with the parent shoot. But these angles of 

 divergence are not always constant, and the Hawthorn, 

 for instance, may afford examples where the uppermost 

 shoots stand off at about 60, those lower down at nearly 

 90, while those at the base of the twig may form an 

 even more open obtuse angle of 100 or so. 



On the whole, the upper and stronger shoots make a 

 more acute angle with the forward part of the parent 

 axis than do those lower down, and although the original 

 angles are not always kept as the shoots age, there can be 

 no question that these general angles of divergence affect 

 the form of branching and of the tree generally, as we 

 shall see when considering that subject. 



