30 
SELECTION BY MAN. 
Chap. I. 
is that we see in them adaptation, not indeed to the 
animal’s or plant’s own good, but to man’s use or fancy. 
Some variations useful to him have probably arisen 
suddenly, or by one step; many botanists, for instance, 
believe that the fuller’s teazle, with its hooks, which 
cannot be rivalled by any mechanical contrivance, is 
only a variety of the wild Dipsacus; and this amount of 
change may have suddenly arisen in a seedling. So it 
has probably been with the turnspit dog; and this is 
known to have been the case with the ancon sheep. But 
when we compare the dray-horse and race-horse, the 
dromedary and camel, the various breeds of sheep fitted 
either for cultivated land or mountain pasture, with the 
wool of one breed good for one purpose, and that of 
another breed for another purpose; when we compare 
the many breeds of dogs, each good for man in very 
different ways; when we compare the game-cock, so 
pertinacious in battle, with other breeds so little quarrel¬ 
some, with everlasting layers ” which never desire to 
sit, and with the bantam so small and elegant; when 
we compare the host of agricultural, culinary, orchard, 
and fiower-garden races of plants, most useful to man at 
different seasons and for different purposes, or so beau¬ 
tiful in his eyes, we must, I think, look further than to 
mere variability. We cannot suppose that all the breeds 
were suddenly produced as perfect and as useful as we 
now see them; indeed, in several cases, we know that 
this has not been their history. The key is man’s power 
of accumulative selection: nature gives successive varia¬ 
tions ; man adds them up in certain directions useful to 
him. In this sense he may be said to make for himself 
useful breeds. 
The great power of this principle of selection is not 
hypothetical. It is certain that several of our eminent 
breeders have, even within a single lifetime, modified to 
