LEAVES, BUDS AND FLOWERS 83 



133. Vigor of leaf -buds. The comparative vigor of 

 leaf-buds on a given shoot depends somewhat upon their 

 location and the length and diameter of the internodes. 

 The terminal bud, when uninjured, is usually the most 

 vigorous one, and the vigor of the buds, as a rule, dimin- 

 ishes as we recede from the terminal bud. The more 

 rapid the growth of the shoot, the less developed, as a 

 rule, are the lateral buds. Cions (386) and cuttings (358) 

 should not, therefore, be taken from excessively vigorous 

 shoots. The more vigorous buds are often more sensitive 

 to cold than the less vigorous ones, since they are usually 

 farther developed the season in which they are formed, 

 hence the terminal buds are most often injured in 

 winter. 



In the potato tuber, which is the thickened terminus 

 of an underground stem (Fig. 34), the most vigorous 

 shoot comes from the terminal bud (the so-called seed- 

 end), hence rejecting this part of the tuber in planting, 

 as has often been recommended, is detrimental to the 

 crop. 



134. Conditions affecting the formation of flower-buds. 

 Most cultivated plants are grown either for their 

 flowers or the product of their flowers, i.e., fruit or seed. 

 But the flower is not an essential part of the plant, and 

 instead of contributing to its welfare, as do the leaves and 

 roots, it actually consumes a part of the plant's reserve 

 food (139). As might be expected, therefore, perennial 

 plants do not always produce an annual crop of flowers, 

 even when well developed in other directions, hence the 

 grower is often disappointed. Since flowers can only come 

 from flower-buds, a knowledge of the laws that govern the 

 formation of these would often be valuable to the cul- 

 tivator. Unfortunately, this subject has received less 



