ioo NATURE < >!■' BUDS 



after a few years l>ut not infrequently they remain alive and 

 become overgrown by the increase of the stem. In such cases 

 the bud grows slowly and maintains itself near the surface of 



the w 1. These buds growing and often branching in the wood 



produce those curlings and twistings in the grain that arc com- 

 monly known as bird's-eye \vo<>d. Dormant buds sometimes de- 

 velop into normal branches, as when a portion of a tree is re- 

 moved and consequently an additional supply of food stimulates 

 them to growth. Buds may also arise upon any part of the 

 stem, ro..t or leaf. These are the so-called adventitious buds 

 and their formation upon roots often accounts for the colonial 

 habit of many trees, plants and shrub-, as in the poplars, Ailan- 

 thus, sumac-, etc. They appear to rise naturally in some i 

 but in other instances their formation is due to the stimulus of 



a wound or some other cause and like the dormant bud they serve 

 to prolong the life of the plant. Richards has shown that when 

 living cells are exposed to the oxygen of the air. owing to a 

 wound, that these cells are stimulated as a result to renewed 

 activity. This doubtless explain- the formation of callus and 



the healing of wounds, as well as the formation of adventitious 

 buds in many cases. Common examples of bud- y\\\c to wounds 

 are seen in the vigorous -hoot- that spring up from the stumps 

 of hard wood trees, pollarded willow-, etc. Some bud- become 

 fleshy owing to the storage of the food and dropping from the 

 plant- serve to propagate new individuals. Examples of this 

 arc seen in the fleshy bud- on the tips of the branches or in the 

 axils of the leaves of the stone-crop and some lilies and in the 

 flower clusters of some onion-. Many aquatic plants have the 

 habit of forming similar buds on the approach of winter. These 



being compact and heavy with food sink to the bottom of the 



ponds in the fall and renew their growth in the spring. 



