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THE BOOK OF NATURE STUDY 



like part. The two carpels forming the pistil are joined by their 

 edges to enclose a single cavity, and the ovules are attached along 

 the lines of junction of the carpels. Ingrowths from these lines 

 of junction form a partition, which divides the cavity of the 

 ovary into two. The fruit shows the result of the further de- 

 velopment of all these parts. It is smooth, or bears stiff hairs like 

 those on the stem. Looked at from the outside, it is readily seen 

 to be formed of two carpels. The curved part of each of these 

 shows three veins, while the lines of junction are of a darker green. 

 If one of the valves be split away from the rest of the fruit the 

 seeds, which have developed from the ovules as a result of polli- 

 nation, will be seen. They are rather large 

 rounded bodies, which are attached by slender 

 stalks to the wall of the ovary. The en- 

 larging seeds have pressed the partition 

 aside, and since some are on the near side of 

 the septum and some on the other half of the 

 fruit, about half the seeds appear covered by 

 the thin partition. If both valves are re- 

 moved, which happens naturally when the 

 ripe fruit opens (Fig. 95, B), they leave the 

 partition stretched between the two strips of 

 ovary wall from which the seeds sprang. 



The seeds then fall to the ground. They 

 are relatively large and have no special 

 method of being scattered to a distance. 

 Each round, smooth seed consists of the seed-coat enclosing the 

 embryo plant. The food material is stored in the thick seed- 

 leaves, which on germination expand as a pair of small, notched, 

 green leaves. These can sometimes be seen at the base of the 

 shoot even of well grown plants. 



B 



FIG. 95. Fruit of the 

 Charlock, showing in 

 B the mode of dehis- 

 cence. (After Baillon.) 



THE SHEPHERD'S PURSE (Capsella bursa-pastoris, Moench). 



The Shepherd's Purse belongs to the same natural family of 

 plants as the Charlock and the Lady's Smock. It is, however, 

 such a common weed, and can be found in flower and fruit from 

 spring to autumn, that a brief account of its main features will be 



