Perhaps no recent work on the subject of embryology has been undertaken with such a dynamic purpose as this contribution. The consideration of embryology as a branch of morphology and anatomy has left its functional and chemical aspects totally unappreciated. Yet the problems of the morphologist and the biochemist so overlap that a unified treatment such as this author presents is most enlightening. The fact that heterogeneities of form and substance originate from the homogeneity of its building substances makes the physiochemical concept of embryology almost a fundamental consideration. "The history of a man for the nine months preceding his birth," said S. T. Coleridge, "would probably be far more interesting and contain events of far greater moment than all the three score and ten years that follow it."
While this subject opens a new concept for many, it has had a humble evolutionary history. The author traces the sporadic