160 ESSENTIALS OF BOTANY 
very much like leaves, and in many cactuses the bracts 
about the flower are so sepal-like that it is impossible to 
tell where the bracts end and the sepals begin (Fig. 117). 
The same thing is true of sepals and petals in such flowers — 
as the white water-lily. In this flower there is a remark- 
able series of intermediate steps, ranging all the way from 
petals, tipped with a bit of anther, through stamens with 
a broad petal-like filament, to regular stamens, as is shown 
Fie. 118. Transitions from Petals to Stamens in White Water-Lily. 
E, F, G, H, various steps between petal and stamen. 
in Fig. 118, £, 7, G, H. The same thing is shown in 
many double roses. In completely double flowers the 
stamens and pistils are transformed by cultivation into 
petals. In the flowers of the cultivated double cherry the 
pistils occasionally take the form of small leaves, and some 
roses turn wholly into green leaves. 
Summing up, then, we know that flowers are altered 
and shortened branches: (1) because flower-buds have, as 
regards position, the same kind of origin as leaf-buds; 
(2) because all the intermediate steps are found between 
bracts, on the one hand, and stamens, on the other. 
