1042 



THE NATURE BOOK 



about the size of a grain of wheat. These 

 will subsequently fall to the ground, and, 

 taking root, produce new plants. We 

 must regard instances such as these as 

 exceptions to that which is the rule 

 amongst plants producing flowers. 



Seeing that the flower is such an impor- 

 tant feature of the plant, it is a matter of 

 interest to consider the relations of the 

 blossom to the other parts of the typical 

 specimen. For the present purpose it 

 will be all-sufficient to think of the flower 

 as consisting of four parts. Starting from 

 the outside of the bloom, we find the calyx ; 

 this consists of a number of sepals, which 

 may be green or coloured. Enveloped in 

 the calyx is the corolla formed of a number 

 of petals usually coloured to a greater or 

 less degree. In the centre of the flower 

 we shall find a number of stamens, these 

 enclosing in their turn the group of carpels 

 which go to make up the pistil. As well, 

 in not a few flowers, there are present a 

 number of external appendages to which 

 has been given the name of bracts. 



BOUGAINVILLKA, AN INTERESTING PI.A\T \UTM 1,1 

 COLOURED BRACTS ROUND INSIGNIFICANT FLOWh 



It has been stated that the calyx of 

 the flower is in some cases green, whilst 

 in other instances it is coloured and petal- 

 like. To state that the sepal is green is 

 the same tiling as saying that the organs 

 to an extent perform the functions of a 

 leaf, and it is interesting to see whether 

 it is possible to trace any further connec- 

 tion between the calyx and the foUage 

 of the plant. The herbaceous Pjeony 

 is well worth an examination with this 

 problem in mind. If a number of speci- 

 mens of this flower be examined, it will be 

 found that quite often the sepals of the 

 calyx are modified leaves. Indeed, time 

 and again it is impossible to determine 

 definitely the exact nature of the organs, 

 and the confusion is all the greater when, 

 as is often the case, a large area of the 

 leaf-like sepal is as gaily coloured as a 

 petal. 



In the common Moon Daisy of the 

 meadows we may trace the whole course 

 of the evolution of the green bracts which 

 encircle the mass of ray florets. If one 

 of the long-stemmed blossoms be 

 examined, it will be found that, 

 starting from the base, where there 

 are the typical leaves of the plant, 

 we shall find that there is a steady 

 decrease in the size of the foliage as 

 we a})])roach the flower head. Finally 

 the green processes lose their cUs- 

 tinctive form altogether, until just 

 below the flower they drift into 

 simple lobes, which bear a striking 

 resemblance to the bracts that en- 

 circle the flower. 



We can thus trace a definite con- 

 nection between the sepals of the 

 flower and the foliage of the plant. 

 Going beyond this, it is not a diffi- 

 cult matter to find a distinct relation- 

 ship existing between the calyx and 

 the corolla. The Tulip is an excellent 

 case in point, for except that the 

 sepals are, of course, on the outside 

 of the petals, there is really nothing 

 to distinguish them. Now, if we 

 observe a large number of cultivated 

 blossoms we shall certainly find that 

 in not a few cases the se]:)als are 

 partly or wholly green, proving be- 

 yond a shallow of a doubt wlience 

 they have their origin. Perhaps a. 

 still more striking proof of the leaf 



[.AC 

 KS. 



