92 Principles of Plant Culture. 



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 

 attention than is due to it. Two principles may be 

 cited, however, which if they do not explain all phe- 

 nomena connected with the formation of flower-buds, 

 are of sufficient general application to have great eco- 

 nomic value, viz. : 



A Plants form flower-buds only when they contain 

 reserve food (84). 



B A water supply insufficient for rapid growth may 

 suffice for abundant food formation (59). 



In support of the first of these propositions, we men- 

 tion : (a) Rapidly-growing plants rarely form many 

 flower-buds because the food is used up in growth as 

 fast as formed, (b) Checking such rapid growth, by 

 removing the growing points of the stem or root (67), 

 or by withholding water, results in an accumulation of 

 food and is often followed by an abundant formation 

 of flower-buds, (c) Obstructing the rootward current 

 of prepared food (79), as by "ringing" (416 g) causes 

 an accumulation of food above the obstruction and is 

 often followed by the formation of flower-buds in that 

 part. 



In support of the second proposition we mention: 

 (a) Florists often bring their plants into bloom at a 

 desired time by withholding water, (b) The flower- 

 buds of most out-door plants are formed during the 

 drier part of summer,* when a restricted water supply 



* Plants that live over winter and bloom in spring, as the 

 apple, strawberry, etc., form their flower-buds the . preceding 

 season. 



