viii CIVIC BIOLOGY 



CHAPTKR PAGE 



XX ill. ('<>NTi:<>I. <».'• ICVCTERIAL DISEASES 231 



XXIW CoNTKUL OF A.MMAL PaKASITES 253 



XXV. Civir PijoHLEAis Relating to Mollusks .... 271 



XX\'l. Crustacea 285 



XX\ ir. rnoBLEMS OF Fish and Fishing 295 



XX^'JI^. Ami'huua : Sirens, Pkoteans, Salamanders, Frogs, 



Ti;ee Frogs, and Toads 313 



XXIX. Reptiles: Crocodiles, Alligators, Turtles, Ter- 

 rapins, Tortoises, Lizards, Snakes 321 



XXX. Practical Laws of Life 330 



XXXT. Knowing How to Know How 316 



XXXI 1. Phogress in Discovery 355 



INDEX 363 



