Mason . — Growth and Abscission in Sea Island Cotton . 463 
importance in initiating abscission until after the inhibition of growth in the 
main axis. 
The results of a recent investigation (7) on correlation in the cotton 
plant is of some interest in this connexion. In the course of that work 
it was found that the growth-rate of the main axis commenced to decline 
as soon as boll-development was initiated, and, moreover, that this retardation 
in the growth-rate could be deferred by suppressing fruit development. It 
was also demonstrated that growth-cessation in the main axis was not due 
to any autogenic change within the terminal meristem, for renewed activity 
of the apparently senescent apical bud occurred after it was isolated and 
budded on a young plant. 
Fig. 5. Percentage of flowers produced daily which were subsequently shed, and daily 
growth-rates of main axis. Gps. I and II. 
As a result of these and other observations, which need not be repeated 
here, it was concluded that the decline in the activity of the apical meristem 
was due to a correlation factor, which was introduced by the development 
of fruit on the basal fruiting branches. It was suggested that it was in 
some way to be associated with a deflexion of growth-promoting substances, 
especially carbohydrates, from the apical to the basal part of the plant. 
It seems plausible to infer that the greater liability of bolls, produced 
after growth-cessation has taken place in the main axis, to undergo 
abscission may also be associated with a deflexion of assimilates from the 
apical to the basal fruiting branches, for the major part of the fruit produced 
during the latter part of the flowering period is, of course, situated on the 
apical part of the plant. Should this assumption be warranted, it would 
