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of light powdery grains, and it has the peculiar property when applied to the 

 stigma, of protruding a tube which burrows down through the length of the 

 style till it reaches the ovary, and when it touches the little bodies found there, 

 and which are called ovules, it impregnates them and they then develop into 

 seeds. The pistil, which is the central organ of the flower, varies very much 

 in appearance ; it may be composed of one or several distinct parts called car- 

 pels, each of which is again composed of three portions. (1) The stigma, 

 which is the extreme tip, and exudes a gummy secretion which retains the 

 pollen grains when they alight upon it, and also exites them into activity to 

 develop the pollen tube. (&) The style, which is simply a stalk to elevate 

 the stigma into a better position for catching the pollen grain, it is not 

 essential and is often absent altogether. (3) The ovary, this is simply a box 

 or case, containing the ovules, which ultimately become the seeds. The 

 simplest form of pistil is seen in the buttercup, where the collection of little 

 yellowish knobs in the centre of the flower are individual carpels, each con- 

 sisting of an ovary containing a single ovule (or seed), and a very short 

 hooked style, the tip of which forms the stigma. Another simple form of 

 pistil is seen in the garden pea, where we have only a solitary carpel, the 

 ovary forms the well known pod, and the little ovules become the familiar 

 peas, which are the seeds of the pea plant. Yery often in shelling peas it is 

 noticed that some of the peas in a pod are small and shrivelled, these are 

 abortive ovules, which through some cause have failed to be fecundated by 

 the pollen tubes, and therefore have never developed into full grown peas 

 (or seeds) containing young plantlets. At the top of the pea-pod (ovary) is 

 seen the style, a short curved stalk, crowned by the stigma. In our wall- 

 flower the ovary is pod-like in its external form, but it is made up of two 

 united carpels, as may easily be seen when it is ripe, for it then splits up in 

 curious fashion, the two outer scales curl upwards and expose two rows of 

 seeds, on each side of a central partition. In the wallflower the style is 

 almost entirely obsolete, and the stigma is the notched top of the ovary. In 

 the primrose an even more complicated pistil is found, in it five carpels are 

 united to form the ovary, the partitions are at first separate, but they soon 

 become obliterated, and the seeds are seen clustered together in the centre, 

 quite free from the surrounding walls of the ovary, the style is a slender pin- 

 like stalk and the stigma is the pin-head at the apex. But through all these 

 varied forms it will be noticed that the essential points remain the same — 

 there must be stamens containing perfect pollen, which in turn must be con- 

 veyed to the stigma, and thence descending to the ovary perform the function 

 of energising and stimulating into vital activity, the hitherto dormant, pas- 

 sive, waiting ovules, which then start into a fresh phase of existence. This 

 process is known as fertilisation. 



