TABLE OF CONTENTS. XI 



CHAPTER VIII. 



The Changes which take pi^oe on the Fifth Day, pp. 232 — 274. 



Appearance on opening the egg, 232. The changes in the limbs, 

 233, 234. The pectoral and peMc girdles ; the ribs and sternum, 234, 

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

 The parachordals and notochord, 237, 238. The trabeculsB, 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 differentiation, 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 differentiation and the fate of the three primary layers, 

 269—273. Summary, 273, 274. 



CHAPTER IX. 



Fbom the Sixth Day to th6 End op iNensATioN, pp. 275 — 303. 



The appearance of distinct avian characters, 275. The foetal 

 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. 

 Nails, 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. 



