18 ELEMENTS OP STRUCTURAL BOTANY. 



Hepatica, some variation. Whilst the normal number is 

 five, some flowers will be found to have as many as nine. 

 24. The stamens are next to be examined, but you 

 should first satisfy yourselves as to whether the calyx is 

 polysepalous or otherwise, and whether it is free from the 

 other floral leaves or not. If your examination be properly 

 made, it will show you that the calyx is free and poly- 

 sepalous. 



The stamens are very much like those of the Buttercup 

 and Hepatica. They are numerous, they have both anthers 

 and filaments, and they shed their pollen through slits on 

 the outer edges of the anthers. They are all separate from 

 each other (polyandrous), and are all inserted on the 

 receptacle. On this latter account they are said to hypogy- 

 nous (below the pistil). 



25. Remove the stamens, and you have left, as before, 

 a head of carpels (Fig. 24). Examine one : there is the 

 ^ lower broad part, which you recognize as the ovary, 

 the very short style, and the sticky stigma. To all 

 appearance the carpels are pretty much the same as 

 those of the two plants already examined. It will 

 not do, however, to trust altogether to appearances 

 Fig. 24. in this case. Cut open a carpel and you find that, 

 instead of a single ovule at the bottom of the ovary, there 

 are several ovules in a row along that edge of the ovary 

 which is turned towards the centre of the flower. 

 The ovary is, in fact, a pod, and, when the seeds 

 ripen, splits open along its inner edge. If you can 

 find one which has split in this way, you can hardly 

 fail to be struck with the resemblance which it Fi 25 

 bears to a common leaf. (Fig. 25.) 



Fig. 24. Head of carpels of Marsh-Marigold. 



Fig. 25. Single carpel, opened to show the two rows of seeds. 



