60 THE ORCHID REVIEW. (FEBRUARY, 1908, 
conditions are sufficiently prolonged in any direction new or changed forms 
arise, which themselves become constant if the altered conditions become 
stable. In the absence of the power to adapt themselves to the changed 
conditions they must succumb, under the law of the survival of the fittest. 
That such evolution has brought about the present enormous diversity in the 
vegetable and animal kingdoms is now almost universally admitted, though 
great difference of opinion exists as to the nature of the machinery employed. 
We have just seen that when two distinct albino parents of fixed 
character are intercrossed the resulting hybrid is coloured ; in other words, 
it returns to the normal. And when individuals of two different species, 
whose characters are in a state of stable equilibrium, are successfully mated 
together, there is a conflict of interests, differing in intensity according to 
the amount of diversity between the parents. The result is a hybrid, whose 
characters are in a state of unstable equilibrium, which in many cases is 
accompanied by retrogression, the characters of the more ancestral, or less 
highly specialised parent being ‘‘ dominant.” If such a hybrid is success- 
fully self-fertilised, or re-crossed with one of the original parents, these 
unstable elements may seize the opportunity to re-arrange themselves 
according to the more stable ancestral pattern, hence we get reversion or 
dissociation of the hybrid character, and when this occurs the separating 
elements would naturally re-arrange themselves according to the law of 
averages. 
The claim that sex is a Mendelian character is not remarkable, for sex 
in the Mendelian sense implies alternative inheritance. But this fails to 
explain its significance. Sexuality is a division of labour, which has per- 
sisted and become universal because of its utility—even to organisms which 
combine both sexes in the same individual. A flower may have the sexes 
in close juxtaposition, and yet possess the most elaborate contrivances to 
prevent self-fertilisation. The very existence of such contrivances shows 
their utility to the race. Self-fertilisation, like in-and-in breeding, tends to 
excessive specialisation and degeneracy, which is continually being checked 
by cross-fertilisation and the conjugation of biparental organisms. 
The fact is Mendelism ignores blended inheritance, with all its utility, 
having no use for it, and it allows no selective influence to its units. It 
implies a mere re-shuffling of existing characters according to nothing in 
particular and without reference to progressive development. It may 
account for the peculiar behaviour of the elements with which it deals, but 
as an adequate theory of heredity it fails completely. Its elements are 
phases of degeneracy. The organisms which best display Mendelian 
phenomena are the degenerate and unfit, the wastrels of their race— 
organisms which would not have been perpetuated under the bracing 
influence of natural selection. 
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