COROLLA. 177 



those of the leaves, even with regard to light itself. 

 And when we consider the elaborate and peculiar se- 

 cretions of a flower, the elastic and inflammable pollen, 

 the honey, and the exquisitely volatile perfume, as we 

 know from the curious discoveries of modern chemistry 

 how great a share light has in the production of such , 

 we cannot but conclude that the petals must be of pri- 

 mary importance with respect to their secretion by its 

 means."* 



Like the calyx, the corolla is sometimes wanting, and 

 hence we have the distinction of naked and apetalous 

 flowers. But it is not always easy to determine when 

 a flower has but one envelope, whether it be a calyx or 

 corolla. The green colour and coarse texture of the 

 former, and the vivid hues and slender fabric of the latter, 

 ^appear in most cases abundantly sufficient to decide the 

 question. But the calyx is not always green, nor is the 

 corolla always gay and lively ; and the exceptions are 

 so numerous as to invalidate every rule established on 

 such a variable basis. 



" Another rule of distinction suggested by Ray was, 

 that the corolla is deciduous, and the calyx permanent ; 

 and the rule is, no doubt, of pretty general applica- 

 tion ; but is loaded with far too many exceptions to be 

 a good one. In the Poppy the calyx falls before the 

 blossom, and in the Hyacinth and Star of Bethlehem 

 the corolla is persistent. 



It had been an opinion of Caesalpinus, that the calyx 

 is merely a continuation of the outer bark of the plant 

 or flower-stalk ; and upon this foundation Linnaeus es- 

 tablishes a test, apparently sufficient to distinguish the 

 calyx from the corolla in all doubtful cases. For, im- 

 proving upon the notion of Caesalpinus, he apprehend- 

 * Dr. Smith. 



