PREFACE
Reading edition
I wish to take this opportunity of expressing my gratitude to Mrs R. B. Goodden and Mr R. M. Y. Gleadowe for the help they have given me in writing this book. With Mrs Goodden the theory was discussed point by point, and her criticisms and suggestions are largely responsible for the final shaping of the argument, as well as for an important development of the theory. To Mr Gleadowe I am indebted for some useful hints, which led to a partial rearrangement of the material, by which the form of the book has been greatly improved.
S. A. McD.
Winton, October 1919.