This book is an easily accessible account of the nature and function of the human embryo. It answers such questions as: How do embryos develop? When can the life of 'a person' be said to begin? What are the main inherited defects in development? Can these be prevented or cured by genetic engineering? Is it possible to make human chimaeras, hybrids, parthenogenones, and clones? How can we overcome human infertility? How are test-tube babies made? What...