Detail from Soemmerring Engravings (image) University of Cambridge Share Print E-Mail Caption In 1799, the German anatomist Samuel Thomas Soemmerring authored 'images of human embryos': two large copper plates with ten pages of Latin text. This article features details from the first plate, depicting 'embryos' between the third week and the fourth month of pregnancy in seventeen steps. It is generally regarded as the first connected series showing not just growth, but also an increase in complexity through human development. Credit Cambridge University Library Usage Restrictions Please credit. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.