CONTENTS xi 



Section 12-9. Lipoids and Sterols in Amphibian Eggs page 1237 



1 2- 10. Lipoids, Sterols, and Cycloses in Fish Eggs 1 239 



1 2-1 1. Phosphorus, Lipoids and Sterols in Arthropod Eggs 1 24 1 

 12-12. Phosphorus, Lipoids, and Sterols in Worm and Echinoderm 1243 



Eggs 



12-13. Lipoids and Sterols in Mammalian Development 1252 



VOLUME III 



Section 13. Inorganic Metabolism 1255 

 13-1. ChangesintheDistributionof Ash during Avian Development 1255 



13-2. Calcium Metabolism of the Avian Egg 1260 



133. Inorganic Metabolism of other Eggs 1 268 



13-4. The Absorption of Ash from Sea-water by Marine Eggs 1 2 7 1 



13-5. The Anion/Cation Ratio 1274 



13-6. Inorganic Metabolism of Mammalian Embryos 1277 



13-7. Calcium Metabolism of Mammalian Embryos 1 285 



Section 14. Enzymes in Ontogenesis 1289 



1 4- 1. Introduction 1 289 



14-2. Enzymes in Arthropod Eggs 1290 



14-3. Enzymes in Mollusc, Worm, and Echinoderm Eggs 1 293 



14-4. Enzymes in Fish Eggs 1 295 



14-5. Enzymes in Amphibian Eggs 1300 



14-6. Enzymes in Sauropsid Eggs 1 303 



14-7. Changes in Enzymic Activity during Development ^30? 



14-8. Enzymes of the Embryonic Body 1310 



14-9. Enzymes in Mammalian Embryos 13 12 



14-10. The Genesis of Nucleases 1326 



1 4-1 1. Foetal Autolysis 1 329 



Section 15. Hormones in Ontogenesis 1335 



1 5 - 1 . Introduction 1335 



15-2. Adrenalin 1 337 



15-3. Insulin 1342 



15-4. The Parathyroid Hormone 1346 



15-5. The Hormones of the Pituitary 1346 



15-6. Secretin 1 348 



15-7. Thyroxin 1348 



15-8. Oestrin and other Sex Hormones ^353 



