vi HORMONES AND HEREDITY 



Mendelian doctrine, so that I am not venturing to 



criticise without experience. I have not hesitated 



to reprint the figure, pubHshed many years ago, of a 



Flounder showing the production of pigment under 



the influence of Hght, because I thought it was 



deskable 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 thev have taken in 



its production. 



J. T. CUNNINGHAM. 



London, June 1921. 



