Species

Darwin and the Darwinians 157

Waterhouse replied, “by relationship I mean merely resemblance.” Darwin, hav-
ing raised the issue of the number of species, then treats species themselves as a
subordinate issue—it is the ways in which higher taxa are to be arranged that he
is most interested in. Shortly thereafter, he mentions species in passing to Hooker:

I was so struck with the distributions of Galapagos organisms &c &c & with the char-

acter of the American fossil mammifers, &c &c that I determined to collect blindly

every sort of fact, which cd bear any way on what are species ... At last gleams of light

have come, & I am almost convinced (quite contrary to the opinion I started with) that

species are not (it is like confessing a murder) immutable.^16

Some years later, he wrote to Hooker about the practical impact of the “question

of species”:

How painfully (to me) true is your remark, that no one has hardly a right to examine

the question of species who has not minutely described many.^17

Yet, in 1853, only four years later, Darwin noted to Hooker that his ideas on spe-

cies had not made all that much difference to his classificatory work:

... in my own work, I have not felt conscious that disbelieving in the permanence of species

has made much difference one way or the other; in some few cases (if publishing avowedly

on doctrine on non-permanence) I shd. not have affixed names, & in some few cases shd.

have affixed names to remarkable varieties. Certainly I have felt it humiliating, discussing

& doubting & examining over & over again, when in my own mind, the only doubt has

been, whether the forms varied today or yesterday (to put a fine point on it, as Snagsby

would say). After describing a set of forms, as distinct species, tearing up my M.S., & then

making them one again (which has happened to me) I have gnashed my teeth, cursed spe-

cies, & asked what sin I had committed to be so punished: But I must confess, that perhaps

the same thing wd. have happened to me on any scheme of work—...^18

He asked Henslow several times for an idea of the number of “close species” in

botanical genera (27 June, 2 July, 7 July 1855) before he managed to make clear that

he was after an impression of how many almost indistinguishable species exist in

large genera. Henslow apparently succeeded, for on 21 July 1855 he replied

I thank you much for attempting to mark the list of dubious species: I was afraid it

was a very difficult task, from, as you say, the want of a definition of what a spe-

cies is.—I think however you were marking exactly what I wanted to know. My wish

was derived as follows: I have ascertained, that APPARENTLY (I will not take up

time by showing how) there is more variation, a wider geographical range, & probably

more individuals, in the species of large genera than in the species of small genera.

These general facts seem to me very curious, & I wanted to ascertain one point more;

viz whether the closely allied and dubious forms which are generally considered as

species, also belonged on average to large genera.^19

(^16) 11 January 1844 [Burkhardt 1996, 80].
(^17) Darwin to Hooker, September 1849 [Darwin 1888, 39].
(^18) Darwin to Hooker, 25 September 1853 [Burkhardt 1996, 128–129].
(^19) Barlow 1967, 182.