THE PLANT 43 



The flowering branches, on the other hand, bear a limited 

 number of flowers, and do not normally yield any further 

 branches. 



The development of these various branches is mainly 

 acropetal and centrifugal, or, in other words, a branch 

 high up the main stem is younger than a lower branch, 

 and the flowers at the outer end of a flowering branch are 

 younger than those nearer the main stem (Fig. 9). Ex- 

 ceptions to this occur in the relative times of development 

 of the two kinds of branches, but in general it is safe to 

 assume that the opening of flowers on the plant body 

 pursues a kind of spiral course, beginning at the inner- 

 most flower of the lowest flowering branch, and ending at 

 the upper and outermost flower of the youngest branch. 



The relations between the two kinds of branches are 



of the utmost commercial importance. If any particular 



Cotton- kind of cotton develops nothing but flowering 



producing branches on the main stem, it will obviously 



Machines, j^ an economical machine for cotton produc- 

 tion (PI. VII., X.) if its leaf area is sufficient to feed all 

 the flowers which it sets, until they open as ripe bolls. 

 If, on the other hand, another kind of cotton does not 

 produce flowering branches on the main stem at all, but 

 waits to bear them on the vegetative lateral branches, it 

 will be slow in coming to maturity, and unsuitable for any 

 district which can provide only a short growing season. 

 This problem has been faced by Mr. Leake in India. 

 Into the further details of branching it is scarcely neces- 

 sary to enter, but it might be noticed that excessive vege- 

 tative branching is undesirable, in that it makes a field 



