170 THE FLOWER. 



intermediate forms. The gradual transition from ordinar}' foli- 

 age to bracts and bractlets is exceedingly common. In color 



and texture it is not rare to 

 meet with bracts which vie 

 with, or indeed surpass, pet- 

 als themselves in delicacy and 

 brightness ; and in such cases 

 they assume a principal office 

 of flower-leaves, that of con- 

 spicuous show for attraction. 

 Scarlet Sage, Painted-Cup 

 (Castilleia) , and the Poin- 

 settia, with other Euphorbias 

 of the conservatories, are ex- 

 amplesof this. In the flowers 

 of Barberry, it is by a nearly 

 arbitrary selection that bractlets are distinguished from sepals ; 

 in Calycanthus, in many kinds of Cactus, and in Nelumbium, 



the same is true 

 as to bractlets, se- 

 pals, and petals ; in 

 Water-Lily (Nym- 

 phaea, Fig. 318), 

 there is a gradual 

 transition from the 

 sepals through the 

 wj llh petals to stamens ; 

 /I /111 in Lilies and most 

 ' ' J^ lily-like flowers, se- 

 I / pals are as brightly 

 (I colored as petals, 



and commonly more 

 or less combined 

 "> with them. When 



the perianth-leaves are of only one set, it is not at all by color or 

 texture that this perianth can be assigned to calyx or to corolla. 

 Normal transitions from a stamen to a pistil could not, in the 

 nature of the case, be expected. 



308. Teratological Transitions and Changes. Teratology is 

 the study of monstrosities. These in the vegetable kingdom 



FIG. 317. Cactus-flower (Mamillaria caespitosa), with bractlets, sepals, and petals 

 passing into each other. 



FIG. 318. Series exhibiting transition from sepals to stamens in Nymphsea odorata 



