4 a 
PREFACE. Vil 
prevent a considerable diffusion of the little book 
“in this country and in the United States, nor its 
translation into more than one foreign language. 
Moreover Mr. Darwin often urged me to pvt ot 
expand the lectures into a systematic popular 
exposition of the topics of which they treat. I 
have more than once set about the task: but the 
proverb about spoiling a horn and not making a 
spoon, is particularly applicable to attempts to 
remodel a piece of work which may have served its 
immediate purpose well enough. 
So I have reprinted the lectures as they stand, 
with all their imperfections on their heads. It 
would seem that many people must have found 
them useful thirty years ago; and, though the 
sixties appear now to be reckoned by many of the 
‘rising generation as a part of the dark ages, I am 
- not wathoat some grounds for suspecting that 
there yet remains a fair sprinkling even of 
“philosophic thinkers” to whom it may be a 
profitable, perhaps even a novel, task to descend 
from the heights of speculation and go over the 
A BC of the great biological problem as it was 
set before a body of shrewd artisans at that remote 
epoch. 
T, dts 33; 
Hopestea, Fasrrotrne, 
April 7th, 1893. 
