TABLE OF CONTENTS 



INTRODUCTION 



Water as a Sphere of Life, p. i. The Invasion of the Waters by Insects, 

 3. The Dominance of Insects, 8. Degrees of Adaptation to Aquatic 

 Conditions, 11. The Surface-film of Water, 12. Equilibrium of 

 Aquatic Insects, 15. The Wintering of Aquatic Insects, 18. Some 

 Cases of Abridged Life-histories, 20. Live Natural History, 24. 

 The Groups to which Aquatic Insects belong, 28. 



CHAPTER I 



AQUATIC BEETLES 



The Whirligig Beetle (Gyrinus), p. 30. Respiration by Tracheal Gills, 36. 

 Dytiscus, 39. The Great Water-beetle (Hydrophilus), 61. Life of 

 Lyonnet, 62, Hydrobius, 87. Donacia, 93. 



CHAPTER II 



FLIES WITH AQUATIC LARV^ 



The Gnat (Culex), p. 97. Experiment on Surface-tension, 100. Corethra, 

 113. Collecting Tackle, 114. Mochlonyx, 121. Chironomus, 122. 

 Microscopic Study of Salivary Glands, 127. Haemoglobin in Blood, 

 130. Development of the Winged Insect within the Larva, 134. 

 Animals which coat their Eggs with jelly, 148. Tanypus, 152. 

 Ceratopogon, 155. Dixa, 157. Dicranota, 164. Pupal Armature 

 for enabling the Insect to creep to the Surface, 169. Ptychoptera, 

 170. Simuhum, 175. Stratiomys, 189. The Rat-tailed Larva (Eris- 

 talis), 19S. J. J. Wilkinson on the Tail of Eristalis, 201 ; on the 

 Pharynx of ditto, 206. Baron Osten Sacken on the Oxen-born 

 Bees of the Ancients, 215. 



