FLORAL SYMMETRY, ETC. 



131 



In IMBRICATE aestivation, the parts of a floral cir- 

 cle, usually five, are placed as seen in Fig. 277. The 

 first leaf is external, the fifth internal, and the inter- 

 mediate ones successively overlap each other. 



The QUINCUNCIAL arrangement is seen in Fig. 278. 

 There are two exterior leaves, two interior, and one 

 intermediate. 



The YEXILLARY arrangement (Fig. 279) is a form 

 of the quincuncial, where one of the petals, that 

 ought to be internal, has, by rapid growth, become 

 larger than the others, and external to them, so as 

 to cover them in. 



In the COCHLEAR arrangement, inequality of de- 

 velopment has produced the order seen in Fig. 280. 



We are reminded of the DECUSSATE arrangement 

 of foliage-leaves by the position of the floral leaves 

 shown in Fig. 281. 



FIG. 281. 



