94 



THE STRUCTURE OF FLOWERS. 



by, or at least is homologous with, the petiolar portion of 



the calycine leaves (Fig. 

 27). 



Phj^llomes, however, 

 are after all but modified 

 portions of caulomes, and 

 petioles are still less de- 

 partures than are blades 

 from the nature of an 

 axis ; so that while in 

 some cases one is inclined 

 to regard the tube as 

 more strictly axial, in 

 others it seem to be more 

 homologous with a sort of 

 fasciation of petioles. 



We shall see directly 

 that the receptacular tube 

 of Prumcs contains the 

 basal portions of the cords 

 proper to the calyx and 

 corolla, so that we might 

 regard the latter as, on 

 the one hand, axial cords 

 preparatory to forming 

 the perianth ; or, on the 

 other, perianthial cords 

 not yet differentiated into 

 petioles. 



Similarly, in the case 

 of monocotyledonous 

 flowers, as the Daffodil, 

 since petioles are less dif- 



Fig. 26.— Pear with hypertrophied and sub-fasciate 

 petioles. 



Fig. 27.— Fuchsia with foUaceons sepals and 

 petals (after Masters). 



