'32 



CHAPTERS ON EVOLUTION. 



part consists of one or more carpels, in each of which we note a 

 lower part called the ovary, wherein the ovules (which become the 

 seeds after fertilisation with the pollen) are contained. Thus much by 

 way of a brief lesson in elementary botany. Now, when we study 

 the bracts, we find that insensibly these have a tendency in many 



flowers to become like the 

 green sepals of the calyx. 

 Look at a Camellia in bud. 

 You will see the numerous 

 bracts, and also the five 

 g sepals, and you will further 

 gain a good idea from this 

 familiar example of the abso- 

 lute identity which may exist 

 between bracts and sepals. 

 In the " Hundred-leaved 

 Rose" you will find illus- 

 trated, in an equally plain 

 and perfect manner, the like- 

 ness of sepals to the green 

 leaves of the rose plants ; 

 and in the geranium the same phenomenon is occasionally seen. 

 From the green calyx with its sepals, to the coloured corolla with its 

 petals the transition is just as readily made. In Camellia Japonica 

 we behold such an interesting and gradual transition from sepals to 

 petals. In some plants (e.g. Indian Cress and Fuchsia) the calyx, 



FIG. 57. STAMENS CHANGING TO PETALS. 



FIG. 58. GOOSEBERRY LEAVES BECOMING SCALES. 



instead of being green, may be coloured ; this fact indicating a 

 transition from calyx to corolla in one way. On the other side, 

 we find the petals may be developed as ordinary leaves, and thus 

 we learn that petals, like sepals, are simply modified leaves. 



The case for the apparent substantiation of Goethe's maxim grows 

 stronger when we approach stamens (Fig. 56, sf) and pistil (/>). If the 

 stamen be in reality a leaf, it is also certain that it resembles a leaf 

 much less closely than the sepal or the petal. The stamen is a 



