VEGETATIVE ORGANS 0]? PLANTS. 285 



point where the base of the leaf or of the leaf-stalk 

 unites with the stem. From these axillary buds, in case 

 their growth is not checked, side-stems or branches 

 issue, which again subdivide in the same manner into 

 branehlets. 



In perennial plants, when young, or in their young 

 shoots, it is easy to trace the nodes and internodes, or 

 the points where the leaves are attached and the inter- 

 vening spaces, even for some time after the leaves, which 

 only endure for one year, are fallen away. The nodes 

 are manifest by the enlargement of the stem, or by the 

 scar, covered with corky matter, which marks the spot 

 where the leaf-stalk was attached. As the stem grows 

 older these indications of its early development are grad- 

 ually obliterated. 



In a forest where the trees are thickly crowded, the 

 lower branches die away from want of light; the scars 

 resulting from their removal, or short stumps of the 

 limbs themselves, are covered with a new growth of 

 wood, so that the trunk finally appears as if it had always 

 been destitute of branches, to a great height. 



"When all the buds develop normally and in due pro- 

 portion, the plant, thus regularly built up, has a sym- 

 metrical appearance, as frequently happens with many 

 herbs, and also with some of the cone-bearing trees, 

 especially the balsam-fir. 



Latent Buds. — Often, however, many of the buds 

 remain undeveloped, either permanently or for a time. 

 Many of the side-buds of most of our forest and fruit 

 trees fail entirely to grow, while others make no progress 

 until the summer succeeding their first appearance. 

 When the active buds are destroyed, either by frosts or 

 by pinching off, other buds that would else remain 

 latent are . pushed into growth. In this way trees 

 whose young leaves are destroyed by spring frosts cover 

 themselves again, after a time, with foliage. In this way. 



