One early, even prescient, use of floral homeotic
mutants to propose a model for development of flowers
[28] led to the proposal that special hormones were
directed to different regions of the developing flower, with
the mutations studied leading floral organs to be formed in
abnormal locations, thereby missing the hormonal influence. While the direct role of genes in the process is not
commented upon, this does introduce a regulatory role for
the hormones, if not the genes, whose role is in positioning
of organ primordia – the paper is an early example of the
use of mutations to develop a mechanistic developmental
model