TABLE OF CONTENTS. xi 



CHAPTER VIII. 



The Ohanoes which take place on the Fifth Day, pp. 2^2 — 274. 



Appearance on opening the egg, 2^2. Tlie changes in the limbs, 

 233. 234- The pectoral and pelvic girdles ; the rihs and sternum, 234, 

 235. The development of the skull, 235—246. The oranium, 235. 

 The parachordals and notochord, 237, 238. The trabeoulfe, 239 — 241. 

 The sense capsules, 241, 242. Membrane and cartilage bones, 242. 

 Skeleton of visceral arches, 242 — 245. Table of bones, 246. The 

 changes in the face, 246 — 251. The posterior nares, 251. Changes in 

 the spinal cord ; its histological diSerentiation, 251 — 254. The central 

 canal; and the posterior and anterior fissures, 254 — 256. Changes 

 in the heart, 256 — 264. Septum in the bulbus and semilunar valves, 

 257 — 259. The cardiac valves, 262. The foramen ovale and Eustachian 

 valve, 262 — 264. The pericardial and pleural cavities, 264 — 269. 

 Histological diSerentiation and the fate of the three primary layers, 

 269 — 273. Summary, 273, 274. 



CHAPTER IX. 



From the Sixth Day to the End op Incubation, pp. 275 — 303. 



The appearance of distinct avian characters, 275. The fcetal 

 appendages during the 6th and 7th days, 276 — 278. During the 

 8th, 9th and loth days, 278. From the nth to the i6th days, 278,279. 

 From the i6th day onwards, 279, 280. Changes in the general form 

 of the embryo during the 6th and 7th days, 280 — 282. During the 

 8th — loth days, 282. From the i ith day onwards, 282. Feathers, 282. 

 NaUs, 283. Ossification, 283. Changes in the venous system before 

 and after the commencement of pulmonary respiration, 283 — 289. 

 Changes in the arterial system, the modification of the aortic arches, 

 289 — 297. Summary of the chief phases of the circulation, 297 — 303. 

 Hatching, 303. 



