162 BOTANY. 



GRAFT BY BUDS. 



A slip of bark, having one or two buds, is exactly fitted to 

 the subject, in the place of a similar slip removed ; the whole 

 is tied up to produce an immediate contact, and to prevent 

 injury from the wind or sun. When the strip of bark con- 

 tains only one bud it is called a shield-graft ; when there are 

 several, and the strip is circular, it is an annular graft. By 

 these means three hundred and thirty-six varieties of apples 

 may be engrafted upon an old Pear tree. 



HERBACEOUS GRAFT. 



This does not differ greatly from the others as to the man- 

 ner of fitting the scions or getting the buds ; but it is practised 

 upon herbs or upon tender shoots of trees. In this way the 

 Melon has been grafted upon the Cucumber, and the Tomato 

 upon the Potato. 



THE FLOWER. 



This name is given to the union of the organs destined to 

 accomplish the reproduction, by germs, of phanerogamous 

 plants. The flower is composed of leaves in a particular 

 stage of transformation^ springing from the extremity of the 

 stem or its branches, and arranged in regular verticels or 

 whorls. These verticels are various in number ; they have 

 a great tendency to become united, and their form differs 

 from that of the leaf in proportion to their distance from the 

 outer edge of the flower. They are divided into four classes : 

 the calyx, externally ; then the corolla and the stamens, and, 

 within them, the pistils which crown the germs or ovules 

 which become seeds. The calyx and the pistils are generally 

 composed of a single verticel; but the corolla and the sta- 

 mens are sometimes composed of many fitting together. 

 Each verticel is ordinarily composed of five pieces in the 

 dicotyledons, and of three in the monocotyledons. The por- 

 tion of the stem, or of the branches, which supports the 

 verticels, is called the torus or receptacle. 



