vi HORMONES AND HEREDITY 



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. 



