X. SPECIAL SENSES 



PAGE 



Special Senses of Heptanchus maculatus 258 



Olfactory organ 258 



Eye 258 



Ear 258 



Innervation 261 



Sensory canal system 261 



Special Senses of Elasmohranchs in General 264 



Olfactory organ 264 



Development of olfactory organ 265 



Gustatory or taste organs 265 



Elasmobranch eye 266 



Structure of adult eye 267 



Finer structure of retina 268 



Development of eye 269 



Accommodation apparatus 269 



Auditory organ 271 



Innervation of ear 273 



Development of ear 274 



Sensory canal system and ampullary and pit organs 274 



Sensory canal system 274 



Function of sensory canal system 279 



Ampullary organs 279 



Pit organs 281 



Bibliography 283 



XI. UROGENITAL SYSTEM 



Urogenital System of Heptanchus maculatus 287 



Urinary system 287 



Genital system 290 



Urogenital System of Elasmohranchs in General 292 



Urinary system 292 



Kidney (Mesonephros) 292 



Ducts of kidney 294 



Finer anatomy of kidney 296 



Nephrostome and segmental duct 296 



Development of nephrostome and segmental duct 298 



Bowman's capsules 299 



Genital system 300 



Genital organs of male 300 



Testes 300 



Finer anatomy of testis 301 



Vasa efferentia 301 



Genital organs of female 303 



Ovaries 303 



Oviducts 304 



Shell glands 304 



Types of egg shells 305 



Uterus 306 



Relation of uterus to embryo 307 



Secondary sexual characters 309 



Bibliography 311 



Index 319 



[xi] 



