LIST OF WOODCUTS. xxi 



FIG. PA GE 



187. Alimentary Viscera and Air- Bladder of Lepidosteus, in situ. (After Balfour 



and Parker.) 230 



188. Intestinal Tract of Perch 231 



189. Intestinal Tract of Siren lacertina 232 



190. Intestinal Tract of Rana esculenta , 232 



191. Diagram of the (Esophagus and Stomach of a Bird 233 



192. Different Forms of Mammalian Stomachs 235 



193. Diagram of the Structure of a Ccelenterate 237 



194. Semidiagrarnmatic Transverse Section of a Portion of the Wall of the 



Intestine. (Combined from the condition seen in both Lower and Higher 

 Vertebrates.) 238 



195. Semidiagrarnmatic Figures of the Mucous Membrane of the Intestine of 



Fishes, showing Intermediate Forms between Longitudinal Folds and 



Bound Crypts 240 



196. Liver of Rana esculenta. (From the ventral side. ) 241 



197. Pancreas and Liver of Frog, to show the Arrangement of their Ducts . . 241 



198. Viscera of Lacerta agilis, in situ 242 



199. Amphioxus lanceolatus, x 2J. (From Gegenbaur, after Quatrefages.) . . 247 



200. Diagram of a Longitudinal Section through the Head of Ammoccetes (A) 



and Petromyzon (B) 248 



201. Longitudinal Section through the Head of Ammoccetes 248 



202. Horizontal Section through the Ventral Side of the Head of a Selachian. 



(Semidiagrammatic.) The floor of the mouth is exposed 249 



203. Horizontal Section through the Ventral Side of- the Head ofSilurus glanis. 



(Semidiagrammatic.) 249 



204. A, B, C, Diagrams showing the Mode of Development of the Lungs . . . 252 



205. Diagram Illustrating the Phylogenetic Development of the Lungs .... 253 



206. Cartilaginous Skeleton of the Laryngo-Tracheal Chamber of Rana escu- 



lenta. (A, from above ; B, from the side.) 254 



207. Larynx of Phyllodactylus europccus. (A, skeleton, and B, musculature of 



larynx.) 254 



208. Larynges of Various Mammals 256 



209. Abdominal Viscera and Air-Sacs of a Duck after the Eemoval of the 



Ventral Body -Wall. (From an original drawing by H. Strasser.) . . . 260 



210. Left Lung of the Duck, in situ. (From an original drawing by H. 



Strasser.) 261 



211. Diagram of the Arrangement of the Bronchi in Mammals. (From the 



ventral side.) 264 



212. Diagram of the Pleural and Pericardial Cavities of Mammals, founded on 



the relations of these parts in Man. (A, horizontal section ; B, transverse 

 section.) 265 



213. Abdominal Pores of Various Vertebrates. (A, Cyclostome ; B, Elasmo- 



branch ; C, Protopterus ; D, Spatularia.) 266 



214. Diagram showing the Primitive Relations of the Different Chambers of 



the Heart 269 



215. Diagram of the Embryonic Vascular System 271 



