The Making of Species 
if the varying individual did not actually trans- 
mit to its offspring its newly acquired char- 
acter, it would undoubtedly transmit to them, as 
long as the existing conditions remained the 
same, a still stronger tendency to vary in the 
same manner. There can also be little doubt 
that the tendency to vary in the same manner 
has often been so strong that all the individuals 
of the same species have been similarly modified 
without the aid of any form of selection. Or 
only a third, fifth, or tenth part of the indi- 
viduals may have been thus affected, of which 
fact several instances could be given. Thus 
Graba estimates that about one-fifth of the 
guillemots in the Faroe islands consist of a 
variety so well marked, that it was formerly 
ranked as a distinct species under the name 
Uria lacrymans. In cases of this kind, if the 
variation were of a beneficial nature, the original 
form would soon be supplanted by the modified 
form, through the survival of the fittest.” Here 
we seem to have a plain statement of the origin 
of new forms by mutation. 
Again, we read (page 34): ‘Some variations 
useful to him (ze. man) have probably arisen 
suddenly, or by one step; many botanists, for 
instance, believe that the fuller’s teasel, 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 
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