that a belief in evolution would entirely alter its character. 
Thus he wrote to Hooker, Sept. 25, 1853 :—“In my own 
work I have not felt conscious that disbelieving in the mere 
permanence of species has made much difference one way or 
the other ; in some few cases (if publishing avowedly on the 
doctrine of non-permanence) I should mot have affixed names, 
and in some few cases should have affixed names to remark- 
able varieties. Certainly I have felt it humiliating, discussing 
and doubting, and examining over and over again, when in my 
own mind the only doubt has been whether the form varied 
to-day or yesterday (not to put too fine a point on it, as 
Snagsby would say). After describing a set of forms as 
distinct species, tearing up my MS., and making them one 
species, tearing that up and making them separate, and then 
making them one again (which has happened to me), I have 
enashed my teeth, cursed species, and asked what sin I had 
committed to be so punished. But I must confess that perhaps 
nearly the same thing would have happened to me on any 
scheme of work.” * 
The essentially subjective character of the results reached by 
the systematist stands out with remarkable force in this as in 
other passages of Darwin’s letters. 
A few years later, on July 30, 1856, he wrote to the same 
friend :—‘‘I differ from him [Lyell] greatly in thinking that 
those who believe that species are not fixed will multiply 
specific names: I know in my own case my most frequent 
source of doubt was whether others would not think this or 
that was a God-created Barnacle, and surely deserved a name. 
Otherwise I should only have thought whether the amount of 
difference and permanence was sufficient to justify a name.” 7 
Disregarding for the moment the term species, it is 
convenient to consider the various groupings of individual 
animals and plants. 
1. Forms having certain structural characters in common 
distinguishing them from the forms of other groups. Groups 
thus defined by Diagnosis may be conveniently called Syndia- 
gnostic (cvv, together ; didyvwors, distinction). 
* ‘Life and Letters,” vol. ii, p. 40. 
+ Ibid. vol. ii, p. 81. 
