VARIATION IN BUDS 161 



to prevent the tree growing too high, a new branch, 

 from just below an ordinary branch, grows up to take 

 its place. The axillary buds are generally small 

 editions of the main and terminal bud of the branch, 

 but are often also protected by the stipules or by the 

 leaf itself, being sunk in a small pit in the base of 

 the leaf stalk, and so quite invisible from outside. 

 This is the case, for instance, with SCHOTIA LATI- 

 FOLIA a tree belonging to the family LEGUMINOSE^, 

 ADANSONIA DIGITATA, and BIGNONIA MEGAPOTAMICA. 

 In BRASSAIA ACTINOPHYLLA there are stipule-like 

 upward extensions of the leaf base which completely 

 cover the axillary bud. 



In IXORA, Coffee and other plants belonging to the 

 family RUBIACE.E, the axillary buds are covered by 

 the large stipules, which are jointed together and form 

 a tube round the axis. The same in the case in RUMEX 

 the Dock, and POLYGONUM and others of that family, 

 where there is also a tube surrounding the axis just 

 above each leaf. 



We see, therefore, that there is considerable variation 

 in buds. There are what we may call naked buds 

 where the end of the branch is without leaves, 

 these only developing later, and is covered only by 

 hairs ; secondly open buds where the end is protected 

 by ordinary foliage leaves; and thirdly specialized or 

 closed buds in which some or all the scales are of a 

 special nature, and must be considered as modified 

 leaves or stipules. 



There are no hard and fast lines of distinction 

 between these three classes, they merge one into 

 another. Naked buds are found generally in dry 

 11 



