10 SOME ASPECTS OF THE INDIGO INDUSTRY IN BIHAR 
types which, however, fall into two main classes as regards branching and root 
development :— 
(1) Bushy types which branch to very varying degrees from the base, the 
branches coming off nearly at right angles to the main axis. There is a 
general correspondence between the method of branching of the stem and 
of the root. The root system is the mirror image of the shoot. In those 
bush types which branch at right angles to the axis, the lateral roots are 
also given off at right angles to the main tap-root. 
(2) Tall vertical types whose branches arise at an acute angle from the 
stem. In the vertical types, the lateral roots arise at an angle very similar 
to that in the case of the branches. 
These general differences are shown in Figs. 1 and 2 and in Plate III. 
Running through both these classes of branching are great divergencies in the 
time of flowering and in the rate of growth. Some are early, others are ex- 
ceedingly late. Some grow slowly, others much more rapidly. All grades of 
intermediates naturally occur. Five main types of root-development have 
up to the present been found :— 
(a) Karly bush types in which nearly all the laterals arise at right angles 
and are concentrated near the surface. Our selected indigo, known as Type 
15, belongs to this group. The root system is shown in Fig. 1. 
Fic, 1. The root-range of an early 
bush type of Java indigo. 
