In how far is the fowl efficient in the generation of the egg, according to Aristotle? And wherefore is the concurrence of the male required? 300 The perfect hen’s egg is of two colours 303 Of the manner in which the egg is increased by the albumen 305 Of what the cock and hen severally contribute to the production of the egg 307 Of the cock and the particulars most remarkable in his constitution 309 Of the hen 313 Of the sense in which the hen may be called the “prime efficient:” and of her parturition 318 Of the manner in which the generation of the chick takes place from the egg 323 In how many ways the chick may be said to be formed from the egg 325 Fabricius is mistaken with regard to the matter of the generation of the chick in ovo 327 What is the material of the chick, and how it is formed in the egg 333 Of the efficient cause of the generation of the chick and fœtus 340 Of the manner in which the efficient cause of the chick acts, according to Aristotle 344 The opinion of Fabricius on the efficient cause of the chick is refuted 350 The inquiry into the efficient cause of the chick is one of great difficulty 355 Of the efficient cause of animals, and its conditions 360 Of the order of generation; and, first, of the primary genital particle 372 Of the blood as prime element in the body 379 Of the inferences deducible from the course of the umbilical vessel in the egg 392 Of the order of the parts in generation from an egg, according to Fabricius 397 Of the order of the parts according to Aristotle 407 Of the order of the parts in generation as it appears from observation 414 Of certain paradoxes and problems to be considered in connexion with this subject 423 Of the nutrition of the chick in ovo 434 Of the uses of the entire egg 442 Of the uses of the yelk and albumen 444 Of the uses of the other parts of the egg 454 An egg is the common origin of all animals 456