Origin and Development of the Composites. 73 
that, in some ways, differ entirely from those concerning 
vegetative organs.” The effect of food and light on the corolla 
in the Compositae has already been noted (cp. Helianthus, V, 21 and 
Chap. IV), and that external conditions may have a marked effect 
even on the inflorescencein the Compositae is shown by the production 
of a solitary capitulum, instead of a compound inflorescence in 
Rudbeckia under adverse conditions (IV, 44), by the seasonal 
variation in the number of ray and disc florets described by Nakano 
(VIII, 19) and others, and also by the floral changes produced by 
injury (IV, 23), grafting (IV, 24) and parasites (IV, 55-56a). That 
the modifications caused by the environment in such details are of 
taxonomic importance is shown by the fact that hairs may be 
diagnostic characters, e.g. in Senecio (25); many of the other 
characters are also used in diagnostic keys to the species. 
The permanence in heredity of epharmonic variations is 
accepted by Warming as proved, but more detailed evidence on 
this point is given by Henslow (27 and X, 38). Cockayne (X, 
15, p. 13) cites quite a number of workers who have given reasons 
for their adherence to this neo-Lamarckian doctrine. Even 
Weismann was “driven to the conclusion that the ultimate origin 
of hereditary individual differences lies in the direct action of 
external influences upon the organism” (55, p. 279 and cp. Mac- 
bride, 35). Whether such inheritance of acquired characters is 
true or not for the species or genotypes (Jordanons, etc.) as 
defined by the Mendelians, it seems certain that many taxonomic 
species (which are based on morphological structure and which 
have not been examined genetically) are the result of the direct 
action of the environment 
The remarkable plasticity of the Compositae is apparent 
throughout most of the work on epharmosis. For example, the 
Compositae give more than one-seventh of the species in New 
Zealand (X, 93, p. 278), but this does not altogether account for 
the fact that Cockayne draws examples from the family for every 
one of his sections on response to ecological factors (X, 15, pp. 
15 sqq.); soil— Cotula Haastii,C. Featherstonii, Senecio antipodus; 
light— Olearia insignis ; wind— Olearia ilicifolia ; water —Cotula, 
coronopifolia ; altitude— Celmisia argentea : as well as for the after¬ 
effect of stimuli — Olearia Lyalli, 0. Colensoi ; for convergent 
epharmony— Celmisia, H&astia, Psychrophyton, and for persistent 
juvenile forms— Helichrysum, 
The most recent example has been worked out by Wall (53a), 
