This was the salutation of a letter sent me by embryologist Hans Holtfreter, shortly before his 90th birthday. And there is much glory here, for the developing organism is a remarkable phenomenon. It respires before it has lungs, digests before it has a mouth, and creates itself anew while it is trying to survive in a hostile environment. It is characterized by a species-specific pattern of orderly change, yet there is enormous variation within the permissible limits. Whereas the finished organism merely maintains its form, the embryo creates it.
Embryology is the science studying the emergence of living order.
This embryology course is designed to introduce you to animal development, not so much as a discipline, but as a way of approaching nature. It will attempt to integrate the study of molecules, cells, tissues, organs, and organisms over time. This year, the course will attempt to integrate the study of animal development within the context of environmental disruptions. Therefore, our laboratory exercises will often compare normal development to the development of the same organism under some environmental condition that may alter its outcome. Don't expect any complete answers.