70 Introduction to Botany. 



means the fruit grower is able to increase very materially 

 the yield of his trees. It seems from observations on dif- 

 ferent forms throughout the plant kingdom that under 

 conditions of good nutrition, if changes occur which check 

 mere vegetative growth, and are not inimical to the life of 

 the plant, then the activity of the plant is apt to manifest 

 itself in the formation of reproductive organs. The results 

 of pruning back branches and roots illustrate this for the 

 higher plants. 



53. Position of Buds. — Buds usually occur at the apices 

 of branches and laterally in the axils of the leaves ; in the 

 latter position they are termed axillary, and in the formei", 

 terminal. Buds which sometimes occur beside or above 

 the axillary buds are called accessory. Sometimes, how- 

 ever, buds occur without order on both stems and roots, 

 and are then called adventitious. Both axillary and acces- 

 sory buds have the same angular divergence as the leaves, 

 and their growth under good conditions results in a sym- 

 metrically shaped plant. Always many buds are formed 

 which never develop into shoots ; or some, after lying dor- 

 mant for years, may resume their growth if accidents to the 

 plant require the production of new shoots on the old 

 branches. Adventitious buds occur normally on the roots 

 of certain plants, such as the white poplar, but they usually 

 appear only as the result of injuries — as illustrated by the 

 numerous shoots which grow forth on the stumps of felled 

 trees. 



54. The Nature of a Bud. — Whether a bud gives rise to 

 leaves or flowers, or to both leaves and flowers, it is essen- 

 tially a miniature shoot whose succession of internodes, 

 nodes, and lateral outgrowths is but a repetition of a simi- 

 lar succession dating back to the germination of the seed, 

 and constituting the whole above-ground body of the plant. 



