292 THE ORCHID REVIEW. (OcToBER, 1914. 
without the other. The inheritance of environment is as important as the 
inheritance of material, the latter indeed only being inherited to a small 
extent, for nearly the whole of the adult is captured from the environment 
and assimilated during ontogeny. In this view the difference between 
somatogenic and blastogenic characters disappears, for all are acquired 
afresh in each generation as the result of response to environmental stimuli 
during development. There is therefore no need to think of germ cells as 
bearers of hereditary characters. Response is purposive to a great extent, 
and results in changes of bodily structure, these being adaptive and following 
definite lines. The whole process of evolution depends on changes of environ- 
ment so gradual that the necessary self-adjustment is possible at every stage, 
for with great or rapid changes development would cease altogether. 
Prof. Dendy next gave a long and very interesting account of the germ 
plasm itself, and the gradually increasing complexity of structure intro- 
duced by the periodically recurring union of germ cells in pairs through 
the sexual process—the amphimixis of Weismann—and remarked on the 
opportunity it afforded for the introduction of diverse characters from 
different lines of descent through hybridisation. He also admitted that 
many new and apparently permanent combinations of character might arise 
by hybridisation, and that the organisms thus produced might have all 
the attributes of what we call distinct species, but that did not justify us in 
accepting the grotesque view that all species have arisen by crossing, oF 
even that the organism is entirely built up of separately transmissible 
“‘unit-characters.” Bateson tells us that ‘‘ Baur has, for example, crossed 
species as unlike as Antirrhinum majus and molle, forms differing from 
each other in almost every feature of organisation.” But surely the latter 
part of the statement cannot be correct, for after all both the parents are 
snapdragons and have all the essential characters of snapdragons. 
It is a most significant fact that the only characters that appear to be 
inherited in. Mendelian fashion are comparatively trivial features of the 
organism that must have arisen during the last stages of phylogeny. This 
is necessarily the case, for any species that are sufficiently nearly related to 
cross are identical as regards the vast majority of their characters. It 1s 
only those few in which they differ that remain to be experimented upom 
and even some of these appear to be non-adaptive, having no obvious 
relation to the environment and no particular value in the struggle i 
existence. They are clearly what Weismann calls blastogenic characters 
originating in the germ plasm, and probably identical with the mutations 
of De Vriese. 
