A germ layer is a collection of cells, formed during animal embryogenesis. Germ layers are only really pronounced in the vertebrates. However, all animals more complex than sponges (eumetazoans and ...

Proceedings of the Royal Society of London. Series B, Biological Sciences, Vol. 134, No. 876 (Jul. 2, 1947), pp. 377-398 (30 pages) A critical study and demonstration of the distribution of yolk ...

Embryonic germ layers are the fundamental organizing principle in animal development. They provide the structural basis from which tissues and organs arise. During early embryogenesis, cells divide to ...

The discovery of a new kind of stem cell challenges conventional thinking about embryonic development. According to the traditional view, the human embryo develops from a three-layered collection of ...