Operational concepts in the history of embryology: methodological study

The aim of the present work is to discuss select concepts called by me “operational concepts.” Despite the fact that they were introduced to biological research from different epistemological perspectives, they have all played an important role in the development of embryology as a science. They have been useful cognitively in planning observations and biological experiments in the area of morphogenesis. They have constituted an essential causal element of theories explaining and describing the course of epigenetic processes.