250 LEAF-ANATOMY OF SC.EVOLA CRASSIFOLIA, 



their extreme stickiness. 'J'hey are, at this stage, cliaracterised 

 by glistening patches of drying secretion, which give them their 

 varnished or lacquered appearance. 



The mature leaves are large, thick, and succulent, and present 

 a dull surface. Despite the fact that the secretion tends to dry 

 up on the expanded portion of the older leaves, the leaf-base is 

 always distinctly sticky, even in the mature leaves. In this 

 manner, the axillary buds are covered by secretion. 



The voung flower-buds are borne in dense, terminal spikes. 

 As is usual in the Goodeniacese, the cah'x is inconspicuous, and 

 the corolla protects the essential parts of the flower. In S. 

 crassifolia, each flower is situated between two bracteoles, and 

 is subtended by a bract, which is glued to the exposed surface of 

 the bud by means of its sticky secretion. The glandular hairs, 

 from which the secretion is derived, are of the same nature as 

 those on the leaves. 



DiSTKI BUTTON OF THE ACTIVELY SECRETING GlANDS. 



It is in the buds that the glandular hairs reach their maximum 

 development. Upon examination of a section through the apex 

 of a shoot, it will be seen that the rudimentary leaves, even 

 before they are completely differentiated from the stem-apex, are 

 provided with numerous, closely-set, mature, actively secreting, 

 glandular hairs. These hairs are more abundantly developed on 

 those surfaces which are exposed earliest. In the bud, there is 

 a continuous production of glandular hairs, the various stages in 

 development being found mingled with the mature glands. These 

 developmental stages are not restricted to the youngest portions 

 of the bud, nor to any particular part of the leaf, but, as will be 

 seen later, apparently any epidermal cell up to a certain stage in 

 development, may form a gland (PI. xxvii., fig.l). In this 

 manner, new glands are provided to keep pace with the increase 

 in surface of the leaf, the secretion of which will prevent the 

 sticky coat from being broken at any point. 



Once the young leaves are freed from the bud, glandular hairs 

 are no longer formed; upon such leaves only, the mature con- 

 dition is found. The distance between these elands tends to 



