46 BOTANY 



of the leaves. The plumule is really the first bud of the 

 seedling, and it shows fundamentally the same structure 

 as the others appearing later on the stem. 



As the seasons of the year in our climate render 

 growth intermittent, confined to little more than half 

 the time, and as the growing shoots are exposed to very 

 unfavourable conditions during the remainder, it is easy 

 to understand that special precautions are called for, 



A B 



FIG. 1 8. Buds of lilac. A, shows the external appearance; 

 B, a slightly magnified section ; C, the bud-scales are reflexed 

 and the leafy shoot has begun to elongate. (After Marshall 

 Ward.) 



that they may develop. If we cut a longitudinal 

 section through one of these buds in the spring before 

 growth is resumed we shall find evidence of such (Fig. 

 1 8 B). The delicate growing cone in the centre will be 

 found to be surrounded by a varying number of leaves, 

 each of which arches over it and is in turn arched over 

 by the next one external to it. The most internal ones 

 are extremely delicate and almost unformed, while the 

 cone itself if magnified will be seen in many cases to bear 

 upon its surface small swellings which indicate that 

 other leaves are in course of formation there. Over 



