Juliet Sutherland, Charles Bidwell
and the Online Distributed Proofreading Team
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
LONDONCONSTABLE AND CO. LTD.1921
My chief object in writing this volume was to discuss the relations ofmodern discoveries concerning hormones or internal secretions to thequestion of the evolution of adaptations, and on the other hand to theresults of recent investigations of Mendelian heredity and mutations. Ihave frequently found, from verbal or written references to my opinions,that the evidence on these questions and my own conclusions from thatevidence were either imperfectly known or misunderstood. This is notsurprising in view of the fact that hitherto my only publications on thehormone theory have been a paper in a German periodical and a chapter inan elementary text-book. The present publication is by no means a thoroughor complete exposition of the subject, it is merely an attempt to statethe fundamental facts and conclusions, the importance of which it seems tome are not generally appreciated by biologists.
I have reviewed some of the chief of the recent discoveries concerningmutations, Mendelism, chromosomes, etc., but have not thought it necessaryto repeat the illustrations which are contained in many of the volumes towhich I have referred. I have made some Mendelian experiments myself, notalways with results in agreement with the strict Mendelian doctrine, sothat I am not venturing to criticise without experience. I have nothesitated to reprint the figure, published many years ago, of a Floundershowing the production of pigment under the influence of light, because Ithought it was desirable that the reader should have before him thisfigure and those of an example of mutation in the Turbot for comparisonwhen following the argument concerning mutation and recapitulation.
I take this opportunity of expressing my thanks to the Councils of theRoyal Society and the Zoological Society for permission to reproduce thefigures in the Plates. I also desire to thank Professor Dendy, F.R.S., ofKing's College for his sympathetic interest in the publication of thebook, and Messrs. Constable and Co. for the care they have taken in itsproduction.
J. T. CUNNINGHAM.
London, June 1921.
INTRODUCTION - Historical Survey Of Theories Or Suggestions Of Chemical
Influence In Heredity
PLATE I. Recessive Pile Fowls
PLATE II. Abnormal Specimen Of Turbot