98 MORPHOLOGY OF THE FLOWER. [LESSON 14. 



plant (bracts or bractlets) into the leaves of the calyx, that it is im- 

 possible to say where the one ends and the other begins. And if 

 sepals are leaves, so also are petals ; for there is no clearly fixed 

 limit between them. Not only in the Carolina Allspice and Cactus 

 (Fig. 197), but in the Water-Lily (Fig. 198) and a variety of 

 flowers with more than one row of petals, there is such a complete 

 transition between calyx and corolla that no one can surely tell hosf 

 many of the leaves belong to the one and how many to the other. 



256. It is very true that the calyx or the corolla often takes the 

 form of a cup or tube, instead of being in separate pieces, as in Fig. 

 194 196. It is then composed of two or more leaves grown 

 together. This is no objection to the petals being leaves ; for the 

 same thing takes place with the ordinary leaves of many plants, as, 

 for instance, in the upper ones of Honeysuckles (Fig. 132). 



257. That stamens are of the same general nature as petals, and 

 therefore a modification of leaves, is shown by the gradual transitions 

 that occur between the one and the other in many blossoms ; es- 

 pecially in cultivated flowers, such as Roses and Camellias, when 

 they begin to double, that is, to change their stamens into petals. 

 Some wild and natural flowers show the same interesting transitions. 

 The Carolina Allspice and the White Water-Lily exhibit complete 

 gradations not only between sepals and petals, but between petals 

 and stamens. The sepals of the Water-Lily are green outside, but 

 white and petal-like on the inside ; the petals, in many rows, grad- 

 ually grow narrower towards the centre of the flower ; some of these 

 are tipped with a trace of a yellow anther, but still are petals ; the 

 next are more contracted and stamen-like, but with a flat petal-like 

 filament ; and a further narrowing of this completes the genuine sta- 

 men. A series of these stages is shown in Fig. 198. 



258. Pistils and stamens now and then change into each other in 

 some Willows ; pistils often turn into petals in cultivated flowers ; 

 and in the Double Cherry they occasionally change directly into 

 small green leaves. Sometimes a whole blossom changes into a 

 cluster of green leaves, as in the " green roses " which are occa- 

 sionally noticed in gardens, and sometimes it degenerates into a 

 leafy branch. So the botanist regards pistils also as answering to 

 leaves. And his idea of a pistil is, that it consists of a leaf with its 

 margins curved inwards till they meet and unite to form a closed 

 cavity, the ovary, while the tip is prolonged to form the style and 

 bear the stigma ; as will be illustrated in the Lesson upon the PistiL 



