TABLE Or CONTENTS. IX 



Page 



CHAPTER SEVENTH. 



OF THE BLOOD AND CIRCULATION 194 



Blood globules in Man, 194 Mammalia, 196 Birds, Reptiles, 

 and Fishes, 197, 198 Blood vessels, 199 Heart, 200 Circu- 

 lation of the Blood in Mammals and Birds, 202 Reptiles, 203 

 Fishes, 204 Crustacea, Mollusca, and Insecta, 205 Capillary 

 Vessels, 207 Circulation of the Blood in the Web of the Frog's 

 foot, 208212 Circulation in the Lungs of the Triton, 213. 



CHAPTER EIGHTH. 



OF RESPIRATION 216 



The Echinoderms, 27 The Tunicata, 218 The Conchifera, 219 

 The Gasteropoda, 219 The Pteropoda, 220 The Cephalo- 

 poda, 220 The Crustacea, 220 The Annelida, 220 Fishes, 

 221 Insects, 223 Air-breathing Vertebrata, 225 Develop- 

 ment of the Lungs, 226 231 Respiration in Gases other than 

 Atmospheric Air, 234. 



CHAPTER NINTH. 



OF THE SECRETIONS 241 



Endosmose and Exosmose, 243 Structure of Glands, 246 Ele- 

 mentary parts of Glands, 263 Origin of Glands, 265 Dis- 

 tribution of the Vessels in Glands, 269. 



CHAPTER TENTH. 

 EMBRYOLOGY .... .... 272 



SECTION I. 

 Of the Egg 27J 



Form of the Egg, 272 Formation of the Egg, 273. 



SECTION II. 



Development of the Young within the Egg .... 278 

 Development of Fishes, 280 289 Development of the Chick, 

 290 Structure of the Egg as just laid, 290 Detachment of the 

 Ovum from the Ovary, and completion of its formation in the 

 Oviduct, 292 Earliest Period in the Development of the Chick, 

 from the first appearance of the Embryo to the first traces of Cir- 

 culation, 295 Second Period of the Development of the Chick, 

 to the Evolution of the Second Circulation, 308 Third Period 

 in the history of the Development of the Incubated Egg : from 

 the commencement of the Circulation in the Allantois to the Ex- 

 clusion of the Embryo, 324 Birth of the Chick, 333 Phy- 

 sical and Chemical changes in the Egg during Incubation, 334. 



SECTION III 

 Zoological Importance of Embryology . . . 336 



