THE HOLLY TREE. 55 



THE BRANCHES AND HOW THEY RAMIFY. 



On a young shoot of Holly the leaves are arranged singly in 

 spiral order with great regularity. 



A corresponding regularity in the twigs which should replace the 

 leaves at a later stage of growth is, however, not to be looked tor. 

 A few words of explanation may be needed upon this point. Many 

 species of trees of dissimilar growth resemble one another in the 

 arrangement of buds upon the twigs : the sycamore and the ash are 

 tvpical of one set of examples, the poplar and the apple ot another. 

 How then account for subsequent divergences ? There are many 

 matters to be taken into consideration. 



In some cases the lateral buds fail, or the branches they pro- 

 duce are not fully developed. In others a flower is produced at the 

 apex of the terminal shoot and the growth of the trees must there- 

 fore be continued by the lateral buds. Again, a comparison between 

 different species of trees makes it evident that the distances between 

 the nodes {i.e., the points whence spring the leaves and subsequently 

 the branches) has a considerable influence upon the general aspect of 

 the tree. In the Holly, which is slow of growth, the internodes are 

 apt to be so short that the branches appear to spring several from 

 the same node, giving a bushy effect to the tree in strong contrast 

 to the growth of the poplar, where the nodes are widely separated 

 and the twigs sparse. Where flower buds are found at the angle of 

 junction of the leaf and twig, and not at the apex of the twig, there 

 will be no lateral branches at the point of inflorescence. But in all 

 these cases, the failure to produce branches exactly corresponding to 

 the position of the leaves is due to a method of growth which is 

 a constant feature in all the trees of a species, however obscured by 

 accidental causes in individual members. 



