I] INFLORESCENCE : BRACTS, ETC. 5 



inner series of expanded, delicate, and coloured structures 

 termed Petals, and of an outer series of green and more 

 leaf-like structures known as Sepals ; but so many peculiar 

 modifications of these interesting organs occur, that they 

 must be treated in more detail later on, and I must 

 confine myself here to repeating that neither petals nor 

 sepals are essential parts of the flower, and to stating that 

 either or both may be associated with either or both of the 

 essential organs. 



It is a remarkable fact that the shoots or branches 

 which immediately bear the flowers, frequently, and in- 

 deed usually, differ in certain respects from those bearing 

 the -foliage only, and in some cases the alterations go so 

 far that the beginner may not recognise these parts of the 

 plant as belonging to the shoot. 



In the commonest cases the differences consist chiefly 

 in departures from the mode of branching prevalent 

 elsewhere on the plant; in alterations in the length, 

 thickness, &c., of the internodes ; and in changes of dis- 

 position, form, and colouring, &c., of the leaves borne in 

 the neighbourhood of the flowers. 



This floral branch-system is known collectively as the 

 Inflorescence ; and the leaves more immediately associated 

 with the inflorescence and flowers are termed Bracts and 

 Bracteoles. 



Before passing to the more detailed description of the 

 foregoing structures, it will be useful to point out that 

 the period of flowering differs considerably in different 

 plants, and particularly in the case of trees and shrubs. 



The power to form flowers is found to be in some way 

 essentially bound up with the power of the plant to lay 

 by stores of reserve-materials, food-stuffs not wanted for 

 its immediate needs in the formation of wood, leaves, &c. ; 

 but it is also evident that such power is dependent to some 



