FOREWORD 



In this short introduction to the comparative study of the brain 

 of fish we have confined oiu* observations to bony fish. The reader 

 will find no reference to the brain of the cartilaginous (elasmobranch)' 

 fish. Our old fi'iend the dog-fish will not appear. This unpleasant 

 animal may be the cause of the backward state of our interest in 

 the neurology of fish. Fifty years ago Ray Lankester was making: 

 pioneer observations on the brain of the dog-fish, but there seem to 

 have been few scientists who have followed liis trail. It is probably 

 true that if investigations had been made on the goldfish or th& 

 roach the interest in these attractive fish would have led to a wider 

 knowledge of the brain structure of fish. This book is a study 

 of the brain of our familiar fresh- water fish, and the common food 

 fishes of the British Isles. Salmon and trout, having a publication 

 of their owti, do not appear. All the figures I reproduce are from 

 my own specimens and drawings with the exception of two text- 

 figures of the brains of the cod and mormyrus : for permission to 

 redraw these I have to thank the Curator of the Royal College 

 of Surgeons of England. In the discussion on the Silence of the 

 Sea, I have referred to passages in Sir WiUiam Bragg's Lectures 

 on " The World of Sound " and to Dr. Beatty's " Hearing in Man 

 and Animals." I have also consulted Cunningham on this subject 

 in the work " Reptiles, Amphibians and Fishes " edited by him. 

 References to other authors are mentioned in the text. A large 

 proportion of the observations described in this work have already 

 appeared in the Proceedings of the Royal Society of London, but 

 the text has been entirely re-wTitten with a considerable amount 

 of new material. 



H. MUIR EVANS. 



