DEVELOPMENT OF THE FLOWER 195 



dicular organs, which are developed in acropetal 

 order, i.e. the smallest or youngest are nearest the 

 centre or apex, while on passing towards the periphery 

 the size regularly increases. 



Put on a higher power, and study these organs in 

 detail, beginning at the centre. 



If the capitulum be young enough, there will be 

 found, as in the vegetative bud, a naked apical cone, 

 with a rather flatter form, but a similar arrangement 

 of tissues to that there observed. Passing from the 

 centre, the external surface assumes an undulating 

 appearance owing to the formation of 



1. Bracteoles, or small leaves, which arise similarly 

 to the leaves as above observed (p. 82), by outgrowth of 

 the epidermis and subjacent tissue : as they grow older 

 they curve towards the centre. Note the formation 

 of hairs of various types from single cells of the epi- 

 dermis, this being a good opportunity for tracing their 

 origin. 



2. The rudiments of flowers, which appear in the 

 axils of the bracteoles, i.e. on the side nearer the apex. 

 These are likewise produced from the epidermis and 

 subjacent tissue ; they are, morphologically speaking, 

 axillary branches. 



The development of the latter into the complete 

 flower must be carefully studied, by comparison of 

 those nearer the centre with older flowers nearer 

 the periphery of the capitulum, or on capitula of 

 various ages. It is obvious that flowers which have 

 been cut in median section will be best fitted for 

 this study. Note the following successive stages of 

 development 



2 



