Transcriber's note: Text enclosed by underscores is in italics (_italics_). A single underscore introduces a subscript (CO_2), and a caret a superscript (B^1). Page numbers enclosed by curly braces (for example: {25}) have been incorporated to facilitate the use of the Alphabetical Index and other page references in the text. * * * * * THE CAMBRIDGE NATURAL HISTORY EDITED BY S. F. HARMER, M.A., Fellow of King's College, Cambridge; Superintendent of the University Museum of Zoology AND A. E. SHIPLEY, M.A., Fellow of Christ's College, Cambridge; University Lecturer on the Morphology of Invertebrates VOLUME V [Illustration] _Frontispiece._ MAP TO ILLUSTRATE THE GEOGRAPHICAL DISTRIBUTION OF PERIPATUS. PERIPATUS By ADAM SEDGWICK, M.A., F.R.S., Fellow and Lecturer of Trinity College, Cambridge MYRIAPODS By F. G. SINCLAIR, M.A., Trinity College, Cambridge INSECTS PART I. Introduction, Aptera, Orthoptera, Neuroptera, and a portion of Hymenoptera (Sessiliventres and Parasitica) By DAVID SHARP, M.A. (Cantab.), M.B. (Edinb.), F.R.S. London MACMILLAN AND CO. AND NEW YORK 1895 _All rights reserved_ "Creavit in cœlo Angelos, in terra vermiculos: non superior in illis, non inferior in istis. Sicut enim nulla manus Angelum, ita nulla posset creare vermiculum."—SAINT AUGUSTINE, _Liber soliloquiorum animae ad Deum_, Caput IX. CONTENTS PAGE SCHEME OF THE CLASSIFICATION ADOPTED IN THIS BOOK ix PERIPATUS CHAPTER I INTRODUCTION—EXTERNAL FEATURES—HABITS—BREEDING—ANATOMY—ALIMENTARY CANAL —NERVOUS SYSTEM—THE BODY WALL—THE TRACHEAL SYSTEM—THE MUSCULAR SYSTEM —THE VASCULAR SYSTEM—THE BODY CAVITY—NEPHRIDIA—GENERATIVE ORGANS —DEVELOPMENT—SYNOPSIS OF THE SPECIES—SUMMARY OF DISTRIBUTION 3 MYRIAPODA CHAPTER II INTRODUCTION—HABITS—CLASSIFICATION—STRUCTURE—CHILOGNATHA—CHILOPODA —SCHIZOTARSIA—SYMPHYLA—PAUROPODA—EMBRYOLOGY—PALAEONTOLOGY 29 INSECTA CHAPTER III CHARACTERISTIC FEATURES OF INSECT LIFE—SOCIAL INSECTS—DEFINITION OF THE CLASS INSECTA—COMPOSITION OF INSECT SKELETON—NUMBER OF SEGMENTS—NATURE OF SCLERITES—HEAD—APPENDAGES OF THE MOUTH—EYES—THORAX—ENTOTHORAX—LEGS —WINGS—ABDOMEN OR HIND BODY—SPIRACLES—SYSTEMATIC ORIENTATION 83 CHAPTER IV ARRANGEMENT OF INTERNAL ORGANS—MUSCLES—NERVOUS SYSTEM—GANGLIONIC CHAIN —BRAIN—SENSE-ORGANS—ALIMENTARY CANAL—MALPIGHIAN TUBES—RESPIRATION —TRACHEAL SYSTEM—FUNCTION OF RESPIRATION—BLOOD OR BLOOD-CHYLE—DORSAL VESSEL OR HEART—FAT-BODY—OVARIES—TESTES—PARTHENOGENESIS—GLANDS 114 CHAPTER V DEVELOPMENT