Essay on embryonic

The material from which the embryo formed already existed in the ovum and during development; this material rearranges itself into layers which fold in various ways to form the embryo. This process of progressive development of the embryo from simple to more complex form is called as epigenesis. Wolff’s work was mostly theoretical.

The Greek philosopher Empedocles was aware of the fact that foetus arose partly from male and party from females semen. He also had knowledge regarding the different stages of development and that heart formed first and nails later. The credit of establishing Embryology as a separate and independent branch of Biology goes to Aristotle.

Essay # 1. Introduction to Embryology: Embryology (GK., embryon = embryo; + logia = discourse) is a study of the origin and development of animals dealing with changes through which a fertilised egg must pass before it assumes the adult state. Fertilisation of an ovum by a spermatozoon results in the formation of a zygote.

Embryogenesis or embryogeny may be defined as the formation and development of embryos. In fact it includes all the changes by which a fertilised ovum or zygote is transformed into an adult. So long as the developing individual remains in the egg, it is called an embryo.