vi Preface 
In reading the essays in proof I have availed myself freely of the 
willing assistance of several Cambridge friends, among whom I wish 
more especially to thank Mr Francis Darwin for the active interest he 
has taken in the preparation of the volume. Mrs J. A. Thomson 
kindly undertook the translation of the essays by Prof. Weismann and 
Prof. Schwalbe ; Mrs James Ward was good enough to assist me by 
translating Prof. Bouglé’s article on Sociology, and to Mr McCabe 
I am indebted for the translation of the essay by Prof. Haeckel. For 
the translation of the botanical articles by Prof. Goebel, Prof. Klebs 
and Prof. Strasburger, I am responsible ; in the revision of the 
translation of Prof. Strasburger’s essay Madame -Errera of Brussels 
rendered valuable help. Mr Wright, the Secretary of the Press 
Syndicate, and Mr Waller, the Assistant Secretary, have cordially 
cooperated with me in my editorial work ; nor can I omit to thank 
the readers of the University Press for keeping watchful eyes on my 
shortcomings in the correction of proofs. 
The two portraits of Darwin are reproduced by permission of 
Messrs Maull and Fox and Messrs Elliott and Fry. The photogravure 
of the study at Down is reproduced from an etching by Mr Axel 
Haig, lent by Mr Francis Darwin; the coloured plate illustrating 
Prof. Weismann’s essay was originally published by him in his 
Vortrdge tiber Descendenztheorie which afterwards appeared (1904) 
in English under the title The Evolution Theory. Copies of this 
plate were supplied by Messrs Fischer of Jena. 
The Syndics of the University Press have agreed, in the event of 
this volume being a financial success, to hand over the profits to a 
University fund for the endowment of biological research. 
It is clearly impossible to express adequately in a single volume 
of Essays the influence of Darwin’s contributions to knowledge on the 
subsequent progress of scientific inquiry. As Huxley said in 1885: 
“Whatever be the ultimate verdict of posterity upon this or that 
opinion which Mr Darwin has propounded ; whatever adumbrations 
or anticipations of his doctrines may be found in the writings of his 
predecessors; the broad fact remains that, since the publication and 
by reason of the publication of The Origin of Species the funda- 
