( S85 )) 
when no longer sustained by selection, If, then, mutual 
fertility be the result of unceasing selection, and mutual 
sterility the inevitable, even if long-postponed, consequence 
of its cessation, it is obvious that Huxley’s difficulty is solved, 
while his suggested experimental creation of sterility by 
selection would not reproduce any natural operation: it would 
afford a picture of a natural result but would be produced 
in an unnatural way. This criticism of Huxley’s contention 
was advanced by the present writer three years ago,* the 
final conclusion being stated in the paragraph printed 
below :— 
““Tf, then, we cannot as yet reproduce by artificial selection 
all the characteristics of natural species-formation, but can 
only imitate natural race-formation, we can nevertheless 
appreciate the reasons for this want of success, and are no 
more compelled to relinquish our full confidence in natural 
selection than we are compelled to adopt a guarded attitude 
towards evolution because our historical records are not 
long enough to register the change of one species into 
another.” T 
Tt was therefore with intense interest and pleasure that I 
read the following sentences in a letter written by Darwin to 
Huxley, Dec. 28, {1862]—sentences which show that criticism 
practically identical had been made by the illustrious naturalist 
nearly forty years earlier. 
‘‘We differ so much that it is no use arguing. To get the 
degree of sterility you expect in recently formed varieties 
seems to me simply hopeless. It seems to me almost like 
those naturalists who declare they will never believe that one 
species turns into another till they see every stage in 
progress.” { 
After reading, in the first volume of ‘‘ More Letters,” the 
often-repeated refutation of Huxley’s objection so clearly and 
strongly expressed in letters received by the objector himself, 
it is surprising that no effect was produced, and that reference 
should have been nearly always made to this supposed flaw in 
the theory of natural selection, whenever the great compara- 
* «The Quarterly Review,” No. 385, January 1901, pp. 368-371. 
1p (hos 1 BHA 
+ ‘More Letters,” vol. i, p. 225, Letter 154, 
