viii GENERAL ZOOLOGY 



CHAPTER PAGE 



XXVI. The Bath Sponge and Some Allies : Porifera . . 283 



XXVII. Amceba and Some Allies : Protozoa 288 



XXVIII. The Past History of Invertebrates and the Be- 

 ginnings of the Vertebrates 299 



XXIX. The Yellow Perch 311 



XXX. The Allies of the Perch : Pisces 321 



XXXI. The Green Frog 332 



XXXII. The Allies of the Frog : Amphibia 344 



XXXIII. The Pine Lizard and its Allies : Reptilia .... 351 



XXXIV. The Domestic Pigeon 368 



XXXV. The Allies of the Pigeon : Aves 377 



XXXVI. The Gray Squirrel 403 



XXXVII. The Allies of the Squirrel : Mammalia 412 



XXXVIII. The Historical Development of Zoology .... 441 



INDEX 453 



