450 Experimental Studies in Indian Cottons. 
base, bearing monopodial secondary branches, or by the length of the 
vegetative period, recorded in days from the time of sowing to the date of 
appearance of the first flower. Both methods are subject to secondary 
influences which render the record approximate only. The inter-relation 
between the two methods of record is given by the coefficient of correla- 
tion, which was found to be 0°681 for a series of plants forming the Fe 
generation of a single cross. 
When a monopodial and a sympodial type are crossed, the heterozygote, 
though intermediate, approximates to the sympodial parent. In the Fz 
generation a series of forms is obtained, of some of which the vegetative 
period is as short as, or shorter than, that of the sympodial parent, while 
it rarely reaches the length of the full monopodial parent. On plotting the 
curve of such a series a single mode only appears, whose value agrees 
approximately with that of the heterozygous form. The partial dominance 
found in the F generation persists here also. In subsequent generations, as 
with the leaf factor, the average value of the length of the vegetative period 
of the offspring approximates to that of the parent. In other words, the full 
sympodial and full monopodial forms will breed pure, but the intermediate 
forms will give rise to a series of forms with vegetative periods of vary- 
ing lengths. There appears to be correlation between the habit and the 
presence of the red colouring matter of the sap; plants possessing the latter 
having a longer average vegetative period. 
The behaviour of this character is, moreover, of great economic import- 
ance. It is essential that plants should be of the sympodial type if their 
cultivation in the United Provinces is to be a commercial success, for the 
monopodial types do not flower in time to give a crop before the winter 
sets in. At the same time, the majority of Indian cottons with a really 
valuable staple belong to the monopodial types. The chief hope of 
improvement of the cotton crop in the United Provinces, therefore, has 
been based on the isolation of pure ae forms with the sa of 
the monopodial type. 
5. Glands of the Leaf—The presence or absence of glands on the 
main veins of the leaf of the Types 4—9, and 11 affords a means of 
sub-dividing these types. Two pure conditions are recognisable—that in 
which the glands are absent (0), and that in which all the leaves of the 
main stem and monopodial branches bear three glands (3-1).* The other 
conditions, in which all the leaves bear one gland or, in general, those of 
* In this notation the first figure denotes the number of glands most commonly found 
on the leaves of the secondary monopodial branches, the second figure the number on 
the leaves of the main stem. 
