DEVELOPMENT OF THE FLOWER. 123 



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 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, leaf-structures, which arise similarly 

 to the leaves as above observed, 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 epider- 

 mis : 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 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 



(a). Form of papilla, conical. 



(&). Apex becomes flattened. 



(c). Periphery of the flattened apex rises into a whorl 

 of five small lobes ; these are the Petals, which are in 

 the mature flower united in a gamopetalous Corolla. 



(d). Between the corolla, and the now depressed 



