The Making of Species 
that certain devices and mechanisms are useful 
to their possessors ; but from our knowledge of 
natural history we are led to think that their 
usefulness is consequent on the degree of per- 
fection in which they exist, and that if they 
were at all imperfect, they would not be useful. 
Now it is clear that in any continuous process 
of evolution such stages of imperfection must 
occur, and the objection has been raised that 
natural selection cannot protect such imperfect 
mechanisms so as to lift them into perfection. 
Of the objections which have been brought 
against the theory of natural selection this is by 
far the most serious.” 
Bateson further pointed out that chemical 
compounds are not continuous, that they do not 
merge gradually each into the next, and suggested 
that we might expect a similar phenomenon in 
the organic world. 
Elsewhere he says: ‘‘ Let the believer in the 
efficacy of selection operating on continuous 
fluctuations try to breed a white or a black rat 
from a pure strain of black-and-white rats, by 
choosing for breeding the whitest or the blackest; 
or to raise a dwarf sweet pea from a tall race 
by choosing the shortest. It will not work. 
Variation leads and selection follows.” 
But Bateson’s views fell upon stony ground, 
because zoologists are mostly men of theory and 
not practical breeders. They laboured under the 
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