Juliet Sutherland, Charles Bidwell
and the Online Distributed Proofreading Team
HORMONES AND HEREDITY
A Discussion Of The Evolution Of Adaptations
And The Evolution Of Species
By J. T. CUNNINGHAM, M.A. (OXON), F.Z.S.
Sometime Fellow of University College, Oxford
Lecturer in zoology at East London College, University of London
LONDON
CONSTABLE AND CO. LTD.
1921
PREFACE
My chief object in writing this volume was to discuss the relations of
modern discoveries concerning hormones or internal secretions to the
question of the evolution of adaptations, and on the other hand to the
results of recent investigations of Mendelian heredity and mutations. I
have frequently found, from verbal or written references to my opinions,
that the evidence on these questions and my own conclusions from that
evidence were either imperfectly known or misunderstood. This is not
surprising in view of the fact that hitherto my only publications on the
hormone theory have been a paper in a German periodical and a chapter in
an elementary text-book. The present publication is by no means a thorough
or complete exposition of the subject, it is merely an attempt to state
the fundamental facts and conclusions, the importance of which it seems to
me are not generally appreciated by biologists.
I have reviewed some of the chief of the recent discoveries concerning
mutations, Mendelism, chromosomes, etc., but have not thought it necessary
to repeat the illustrations which are contained in many of the volumes to
which I have referred. I have made some Mendelian experiments myself, not
always with results in agreement with the strict Mendelian doctrine, so
that I am not venturing to criticise without experience. I have not
hesitated to reprint the figure, published many years ago, of a Flounder
showing the production of pigment under the influence of light, because I
thought it was desirable that the reader should have before him this
figure and those of an example of mutation in the Turbot for comparison
when following the argument concerning mutation and recapitulation.
I take this opportunity of expressing my thanks to the Councils of the
Royal Society and the Zoological Society for permission to reproduce the
figures in the Plates. I also desire to thank Professor Dendy, F.R.S., of
King's College for his sympathetic interest in the publication of the
book, and Messrs. Constable and Co. for the care they have taken in its
production.
J. T. CUNNINGHAM.
London, _June_ 1921.
CONTENTS
INTRODUCTION - Historical Survey Of Theories Or Suggestions Of Chemical
Influence In Heredity
CHAPTER I - Classification And Adaptation