SEPALS AS PETALS 207 



petals are much bigger than in the other cases, and 

 thicker and rather hairy at the top, where they are 

 exposed beyond the calyx. In these cases the an- 

 thers and ovary are protected partly by the petals. 

 In GOSSYPIUM, the cotton plant, there are three large 

 green leaf-like organs (bracteoles) attached to the 

 pedicel just below the calyx, and these stand up and 

 enclose the bud, but spread out as the flower opens. In 

 THESPESIA there are also three bracteoles, but these are 

 small and fall off sometime before the flower opens, 

 and we should notice that, in correspondence with 

 this, the ends of the petals are thicker than they are 

 in GOSSYPIUM. We find the same sort of thing in 

 some species of LEUCAS, where the calyx teeth are 

 short and the upper lip of the corolla is very hairy. 



Again in the COMPOSITE (the Sunflowers, etc.), 

 and in the DIPSACACE^E (the Teazels, and Scabius), 

 the flowers are protected in the early stages by the 

 bracts of the involucre, and the calyx teeth are 

 reduced to mere hairs. 



2. On the other hand, the petals are in some cases 

 absent and their place taken by sepals which are 

 then very large and brightly coloured, just like petals, 

 as happens, for instance, in ANEMONE, We say that 

 it is the petals and not the sepals that are absent 

 in this case, because we have agreed to call the 

 outermost circle "of floral organs sepals, and where 

 they are undeveloped there is always a ring or some- 

 thing else to show it. It is only another instance 

 of what we have already learnt in our study of seeds, 

 thorns and tendrils that, in determining the nature 

 of an organ, we must go, not by its appearance, which 



