TABLE OF CONTENTS 



13. THE ORGANS OF HEARING 145 



The general featiires 145 



The tympana 145 



The chordotonal organs 145 



The scolopale and the scolopophore 146 



The integumental and the subintegumental scolopophores 146 



The structure of a scolopophore 146 



The structure of a scolopale 147 



The simpler forms of chordotonal organs 147 



The chordotonal ligament 147 



The chordotonal organs of larvse 148 



The chordotonal organs of the Locustidae 148 



The chordotonal organs of the Tettigoniidae and of the Gryllida;. . . 149 



The trachea of the leg 1 50 



The spaces of the leg 151 



The supra-tympanal or subgenual organ 151 



The intermediate organ 152 



Siebold's organ or the crista acustica 152 



Johnston's organ 1 52 



14. SENSE-ORGANS OF UNKNOWN FUNCTIONS 



The sense-domes or the olfactory pores 154 



15. THE REPRODUCTIVE ORGANS 



The general features 156 



Secondary sexual characters 157 



The reproductive organs of the female 157 



The general features of the ovary 157 



The wall of an ovarian tube 158 



The zones of an ovarian tube 158 



The contents of an ovarian tube 158 



The egg-follicles 158 



The functions of the follicular epithelium 159 



The ligament of the ovary 1 59 



The oviduct 1 59 



The egg-calyx 1 59 



The vagina 1 59 



The spsrmatheca 159 



The bursa copulatrix 1 59 



The colleterial glands 160 



The reproductive organs of the male 160 



The general features of the testes 160 



The structure of a testicular follicle 161 



The spermatophores 1 62 



Otlier structures 162 



