BUDS. 89 



and other forest trees in our climate, and also in most of onr 

 common herbaceous phants : they are called Exogenous stems, 

 signifying to grow outwardly ; plants with such stems spring 

 from seeds with two cotyledons^ and are therefore called dicoty- 

 ledonous plants. Stems which grow internally^ as j^alms and 

 grasses, are called Endogenous^ signifying to grow inwardly ; 

 the wood, instead of circling around the first formed substance, 

 is pushed outward by the development of new fibers in the cen- 

 ter ; this kind of stem is peculiar to plants whose seeds have 

 but o^ie cotyledon^ and are therefore called monocotyledonous. 



LECTUKE YIII. 



BUDS. 



46. A BUD is a protuberance formed by a new shoot. The 

 normal situation of the bud is at the nodes, and it usually 

 appears at the axil of the leaf. In the embryo is a short axis 

 or stem crowned by two or more undeveloped leaves, or a hud. 

 The apex of a growing stem is always crowned with the rudi- 

 ments of a new plant, or with a hud. The scales of buds usu- 

 ally envelop each other closely ; the exterior ones being dry 

 and hard, the interior moist, and covered with down ; they are 

 also furnished with a kind of resin, or balsam, which prevents 

 the embryo from being injured by too much moisture. Buds 

 have been known to lie for years in water, without injury to 

 the germ within. The sap is the great fountain of vegetable 

 life ; by its agency new buds are yearly formed to replace the 

 leaves and flowers destroyed by the severity of winter. 



If we plant a slip of Geranium, it either sprouts from the axil of a leaf, or from 

 knots in the stem, which answer the same purpose as the leaf, bj sL'ghtly inter- 

 rupting the circulation of the juices, and thus affording an accumulation of sap 

 necessary for the production of a new shoot. The different periods of the bud 

 have been distinguished as follows : the point or nucleus which first appears, is 

 called the eye ; when this begins to swell so as to be apparent, it is termed the 

 hvtton ; and in a more mature state the had. Herbs and shrubs have buds, but 

 these usually grow and unfold themselves in the same season, and are destitute 

 of scales ; while the buds of trees are not perfected in less than two seasons, and, 

 in some cases, they require years for their full development. 



a. Nature is bounteous in her provisions, and lays in a large stock of these rudi- 

 ments of future plants, so that when some fail of maturing, others are always 

 ready to take their places. In the spring, the growth of the leaves and branches 

 of trees is rapid ; but as summer advances, tlie progress of vegetation seems almost 

 suspended. Yet nature, uistead of resting in her operations, is now busy in pro- 



Monocotyledonous stems. — 46. Bud— Its normal situation — Bud in the embryo — In a growing stpni — 

 Scales of buds— Agency of sap— The eye, button, and bud— Herbs and shrubs destitute of sraly ))uil» 

 —a. Period in which the formation of buds commences. 



