Developments of the Avian Embryo

One: Behaviour.- 1. Incubation Requirements.- 1.1 Introduction.- 1.2 Requirements of the embryo of the domestic fowl.- Heat — Humidity — The gaseous environment — Egg position and change of position.- 1.3 Incubation requirements of other domestic species.- 1.4 Incubation in wild birds.- — Incubation sites — Warming of the eggs — The problem of cooling — The continuity of attentiveness — Humidity — The gaseous environment — Egg shifting or turning — Hatching success.- 2. General Development, Postural Changes, Activity and Relationship between the Embryo and Other Structures within the Shell.- 2.1 Changes in size, posture and position in the domestic fowl embryo during incubation.- 2.2 Embryonic activity during incubation in the domestic fowl embryo.- Passive movements — Active, spontaneous movements — Significance of spontaneous activity.- 2.3 Hatching and emergence in the fowl.- 2.4 Structural and behavioural development in species other than the fowl.- Structural and behavioural development during the first two-thirds of incubation — Pre-hatching and hatching behaviour in species other than the fowl.- 2.5 The characterization and scoring of embryonic movements.- Terms used to describe embryonic activity — The quantification of embryonic motility.- 3. Vocalization and Communication in the Natural Situation.- 3.1 Species which can vocalize before hatching.- 3.2 Prerequisites for the onset of vocalization.- 3.3 Types of stimulation followed by embryonic vocalization.- 3.4 Effects of embryonic vocalization on the parent.- 3.5 Long-term effects of embryo/parent interaction.- 3.6 The earliest stage at which embryos become responsive to parental calls.- 4. Effects of External Stimulation on Embryonic Activity, Rate of Development and Time of Hatching.- 4.1 Introduction.- 4.2 The synchronization of hatching in quail.- Effects of stimulation on the time of hatching — Problems arising from changes in hatching time — Signals which have accelerating or retarding effects on neighbouring eggs — Effects of accelerating and retarding signals on the rate of development.- 4.3 Effects of accelerating and retarding stimulation in domesticated species.- 4.4 Effects of light in the fowl.- 4.5 Embryonic interactions in wild species.- 4.6 The embryonic response to stimulation.- 5. The Nervous System.- 5.1 Introduction.- 5.2 Development of activity in different parts of the nervous system.- Spontaneous activity — Responses of the brain to stimulation.- 5.3 Neural mechanisms mediating early motility in the embryo of the domestic fowl.- The development of motor and sensory areas in the spinal cord —The part played by the brain in controlling periodic, random motility — Independence of periodic, random motility from sensory input — Areas of the brain which influence periodic random motility.- 5.4 Neural mechanisms mediating pre-hatching and hatching behaviour.- — The spinal cord and pre-hatching behaviour — The midbrain and pre-hatching behaviour — The forebrain and hatching — The cerebral EEG during hatching.- 5.5 Neural correlates of embryonic motility.- Nervous activity in the spinal cord between I5 and I9 days — The polyneuronal burst discharge between days 5 and 20 — Neural correlates of motility — Communication between different parts of the spinal cord.- 5.6 Inhibition.- 5.7 Sleep and arousal.- 6. The Development of Sensory Systems.- 6.1 Introduction.- 6.2 The non-visual response to light.- — Evidence for a non-visual response to light in newly hatched pigeons — Evidence for a non-visual response to light in pigeon embryos.- 6.3 Tactile sensitivity.- The onset of sensitivity — The type of movement evoked by tactile stimulation — Response decrements with repeated stimulation.- 6.4 Vestibular sensitivity.- 6.5 Proprioception.- 6.6 Hearing.- Development of the auditory system — The age of onset of auditory sensitivity — The development of auditory sensitivity — The ontogeny of auditory discrimination.- 6.7 Taste.- The sense of taste in birds — Development of a taste sense in the embryo.- 6.8 Vision.- Development of the visual system — Response to light in the domestic fowl — Colour vision — The behavioural response to light — Effects of previous experience on the responsiveness of the visual system — A comparative view of the onset of visual function — Effects of light on the embryo in ovo.- 6.9 Olfaction.- The olfactory sense in birds — Development of olfaction in the embryo.- 7. Conditioning of the Chick Embryo and Conclusions to Chapters 1–7.- 8. The Newly Hatched Bird.- 8.1 Introduction.- 8.2 Requirements of the neonate.- Warming and cooling — Righting and standing — Social attachments in young birds — Feeding behaviour — Oiling and preening.- 8.3 What is new in the life of the neonate?.- 8.4 Effects of new environmental stimuli on neural mechanisms.- 8.5 Conclusions.- Two: Physiology.- 9. Gaseous Exchange and Oxygenation of the Embryo.- 9.1 Gross oxygen consumption and carbon dioxide production.- 9.2 The shell and the chorio-allantois.- Structure of the shell — Development and structure of the chorio-allantois.- 9.3 Physical aspects of gaseous exchange.- Oxygen — Carbon dioxide — The air space — Maximum gaseous flux during incubation.- 9.4 The blood and vascular system.- Red blood cells — Blood volume and pressure — The heart — Haemoglobins — Oxygen affinity of haemoglobins — Blood gases.- 9.5 Efficiency of the chorio-allantois as a surface for gaseous exchange.- 9.6 Effects of altitude.- 10. Nutrition and Utilization of Albumen and Yolk.- 10.1 Nutrition of the developing bird.- Essential amino acids — Carbohydrate — Essential fatty acids — Minerals, trace elements and vitamins — Energy sources.- 10.2 Gross composition of the egg and the changes during incubation.- 10.3 The albumen and its utilization.- Composition — Absorption — Functions.- 10.4 The yolk and its utilization.- Composition — The yolk sac membrane — Utilization of yolk.- 10.5 Energy metabolism.- 10.6 The sub-embryonic fluid.- 11. Acid-base Balance.- 11.1 Blood pH and $${P_{C{O_2}}}$$.- 11.2 Plasma bicarbonate.- 11.3 The compensation of respiratory acidosis.- The sources of bicarbonate — The possible role of the kidney in excreting bicarbonate.- 12. Excretion and Water Balance.- 12.1 Introduction.- 12.2 The development of the excretory system.- The pronephros — The mesonephros — The metanephros.- 12.3 Synthesis of nitrogenous excretory products.- Metabolism of the amino group — Urea — Uric acid.- 12.4 The pattern of excretion during development.- Excretory products — The organs of excretion.- 12.5 The allantoic sac.- Storage of excretory products — Active transport by the allantoic endoderm.- 12.6 Water balance.- Sources of water — Factors affecting water loss — Gross movements of water within the egg — Conservation of water.- 13. Hormones in Development.- 13.1 General introduction.- 13.2 Thyroid hormones.- Development of the thyroid glands — Synthesis and secretion of hormones — Metabolic effects of the thyroid hormones — The thyroid and hatching.- 13.3 Parathyroid hormone and calcitonin.- Introduction—Development of the parathyroids and ultimo-branchial bodies — Secretion of parathormone and calcitonin — Significance in development.- 13.4 Adrenal hormones.- Development of the adrenal glands — Synthesis and secretion of adrenal hormones — Significance of adrenal cortical hormones in development — Significance of adrenal medullary hormones in development.- 13.5 Pancreatic hormones.- — Development of the endocrine pancreas — Structure and secretion of insulin and glucagon — Role of insulin in development — Role of glucagon in development.- 13.6 Gonadal hormones.- Development of the genital system — Synthesis and secretion of gonadal hormones — Significance in development.- 13.7 Hypophyseal hormones.- — Development of the hypophysis — Secretion of hormones by the pars distalis — Significance of hypophyseal hormones in development.- 13.8 Glands of uncertain endocrine status.- — Bursa of Fabricius — The pineal gland.- 14. Mobilization and Utilization of Calcium Stores.- 14.1 Physiological aspects of calcium transport.- 14.2 The sources of calcium and gross changes during incubation.- 14.3 The role of the chorio-allantois in calcium transport.- Solubilization of calcium — Active transport by the chorionic ectoderm.- 14.4 Changes following calcium resorption.- The shell — Plasma calcium.- 14.5 Mineralization of the bones.- 15. Physiology of Hatching.- 15.1 General introduction.- 15.2 Pulmonary respiration.- — The respiratory system — The onset of breathing: the pulmonary stimulus — The development of the breathing pattern.- 15.3 Circulatory and associated changes.- 15.4 Pipping.- 15.5 Active hatching.- 15.6 Withdrawal and fate of the yolk sac.- 15.7 Oxygenation and energy metabolism during hatching.- 16. The Neonate.- 16.1 Introduction.- 16.2 Thermoregulation.- Ontogeny of thermoregulation — Mechanisms of thermoregulation.- 16.3 The alimentary tract.- 16.4 Immunological competence.- 16.5 Concluding remarks.- Appendix 1: Chronology of development in the domestic fowl.- Appendix 2: Development of the chick embryo in relation to the shell, yolk, albumen and extra-embryonic membranes by Beryl Tolhurst.- References.