ORGANIC STABILITY 125 
of no small importance in disposing of many minor 
objections to the doctrine of transmutation.’* 
The first person to formulate a more or less precise 
view upon the subject of definite variation was Francis 
Galton, although this author never entered into the 
question at any great length. Galton’s attitude 
towards the problem in its early stages may be gathered 
from the following quotation from his ‘ Natural In- 
heritance ’: ‘The theory of natural selection might 
dispense with a restriction for which it is difficult to 
see either the need or the justification—namely, that 
the course of evolution always proceeds by steps that 
are severally minute, and that become effective only 
through accumulation. That the steps may be small, 
and that they must be small, are very different views ; 
it is only to the latter that I object, and only when the 
indefinite word “‘ small” is used in the sense of “‘ barely 
discernible,” or as small compared with such large sports 
as are known to have been the origins of new races.’ 
But more than this, the idea of the existence of 
stable forms, such as may be supposed to have arisen 
by large and sudden variations, is very well expressed 
by Galton in his division of varieties into the three 
groups of primary types, subordinate types, and mere 
deviations from the latter. A most luminous analogy 
is afforded by the three types of public vehicles which 
at the end of the nineteenth century were character- 
istic of the streets of London ; and it is impossible to 
resist quoting Galton’s account of them. These three 
* ‘Collected Essays,’ vol. ii., p. 77. 
ft ‘ Natural Inheritance,’ p. 32. 
