CHAPTER I

PAGE

INTRODUCTION 1

Distinction between creases and ridges 1

Origin of the inquiry 2

Summaries of the subsequent chapters 3-21

Viz. of ii., 3; iii., 4; iv., 5; v., 5; vi., 8; vii., 10; viii., 12; ix., 13; x., 14; xi., 16; xii., 17; xiii., 19;