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