FLOWERING PLANTS INTRODUCTORY ,,, 



In the centre of the flower a group of small green bodies will 

 be seen. These are the carpels, and together they make up the 

 region of the flower called the pistil. The numerous carpels are 

 inserted separately on the upper part of the floral receptacle, 

 and are much less leaf-like than the other parts of the flower. 

 They are best seen on removing the sepals, petals, and stamens 

 from a flower, or on cutting a flower in half. A single carpel 

 can also be removed from the receptacle with the point of the 

 knife, and will be found to have been attached by a narrow 

 base, above which it suddenly widens out to narrow again 

 to a fine tip, which curves outwards. The whole carpel is 

 flattened laterally ; the lower part has a pale green colour, while 

 the narrower upper portion is yellowish. Each carpel is really 

 a hollow body, and corresponds to a leaf bent round so as to 

 enclose a cavity. Within this cavity is a small stalked body, 

 which is destined later to develop into a seed. This little 

 body is the ovule, and can be seen with the lens through the 

 translucent wall of the lower part of the carpel. With care it 

 is possible to open the latter, and remove the ovule on the 

 tip of the knife. The wider lower part of the carpel, within 

 which the ovule is contained, is called the ovary, the narrower 

 part above is the style, while the small rough tip to this is 

 the stigma. The pistil of the Buttercup is thus seen to consist 

 of a number of separate carpels, each of which encloses a single 

 ovule. 



Before the ovule can develop into the seed some of the pollen, 

 which we have seen to be formed in the stamen, must be brought to 

 the stigma. The pollen may be derived from the stamens of the 

 same, or of another flower, and the process of transferring it 

 from the anther to the stigma is known as pollination. Pollina- 

 tion is followed by other changes, into which it is unnecessary to 

 enter here, but it must be understood that one of the two cells, 

 which unite to give rise to the new plant in the seed, comes from 

 the pollen grain, while the other is contained in the ovule. It 

 is because these two cells must be brought together by the transfer 

 of pollen to the stigma, and the processes that follow on this, 

 that the reproduction effected by the flower is spoken of as 

 sexual, and contrasted with vegetative reproduction. The 



