Researches that have benefited from access to these archival sections

Three professors who were active during the first half of the 1900s at the Institute of Anatomy of the University of Zürich, and who inaugurated and compiled the collection of serial sections, were engaged in embryological research:

• Professor Walter Hermann Felix (Director: 1896 - 1930) undertook fundamental investigations into the development of the urogenital system, and furnished evidence for the existence of the double formation of the metanephros.
• Professor Walter Vogt (Director: 1930-1935) was an experimental embryologist, who introduced the use of vital marking of the young amphibian gastrula with dye-soaked pieces of agar.
• Professor Gian Töndury (Director 1945-1977) worked on the prenatal development of the spine (with special consideration of the intervertebral discs), on facial development (focusing on the formation of the facial clefts) and the development of the cardiac lymphatic system. Töndury’s work on developmental disorders arising in embryos because of maternal infection with viral agencies, such as Rubella, during the early stages of pregnancy won him worldwide renown.

Professor Gisela Molz dealt with morphologic variations as possible explanations for “sudden infant death”. She helped establish a unique collection of archival sections of embryos of mothers who had contracted viral infections, particularly Rubella, during early pregnancy.

Professor Karl Theiler, a collaborator of Professor Töndury, devoted his research efforts to the development of the house mouse, which he divided into 26 prenatal and 2 postnatal stages. He wrote an influential book in which his findings are documented [1].

Professor Adolf Faller, a colleague of Professor Töndury in Zürich, was appointed as head of Anatomy in Fribourg (Switzerland). Faller published on embryology, histology, and ethical problems. He is the author of a popular book on Human Anatomy, now in its twentieth edition.

1. Theiler, K., The House Mouse: Atlas of Mouse Development. 1972: Springer-Verlag, N.Y.

Other archival collections of histological sections

Wilhelm His (1831-1904), Professor of Anatomy at the University of Basel and later at the University of Leipzig, introduced one of the first microtomes that could cut an entire embryo into a series of sections. He pioneered the method for reconstructing three-dimensional drawings and models from histological slice and published a “Normentafel”[1, 2], a forerunner for the later Carnegie tables.

The Carnegie collection (https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_Collection) was used extensively to develop a model to assess the developmental age or “stage” of normal embryonic development (now known as the “Carnegie stages”) [3].

The Kyoto collection (https://human-embryology.org/wiki/Kyoto_Collection) comprises demographic and behavioral data appertaining to women from whom the embryo derives. The project was facilitated by the access of healthy Japanese women to therapeutic abortions according to the Maternity Protection Law. This collection is used to study embryogenesis, and to analyze the etiology of congenital malformations [4].

The Dr. Hill Collection The Embryology webpage developed by Dr. Mark Hill, of the University of South Wales, is a rich source of information appertaining to human embryology (https://embryology.med.unsw.edu.au). It also contains original images that have been prepared from serial sections through embryos and a list of organs. Dr. Hill initiated the Digital Embryology Consortium, which has the aim of scanning archival histological sections through human embryos at various institutions worldwide (https://embryology.med.unsw.edu.au/embryology/index.php/Digital_Embryology_Consortium_-_Information).

The Blechschmidt Collection at the University of Göttingen was used to develop methods for reconstructing the human embryo from serial sections and to generated large models describing the embryonic stages of human development [5, 6].

The HDBR resource The Human Developmental Biology Resource (HDBR), founded in 1999, is a tissue bank in which biological samples are collected and stored with the donor’s written permission to be used for research purposes [7]. The HDBR atlas also contains annotated, high resolution histological sections through human embryos (https://hdbratlas.org/histology.html) and a database of gene expression profiles (https://hdbratlas.org/background.html).

1. His, W., Anatomie menschlicher embryonen. Vol. 1. 1882, F.C.W. Vogel, Leipzig.
2. Hopwood, N., Producing development: The anatomy of human embryos and the norms of Wilhelm His. Bull Hist Med, 2000. 74(1): p. 29-79.
3. O'Rahilly, R. and F. Muller, Developmental stages in human embryos: revised and new measurements. Cells Tissues Organs, 2010. 192(2): p. 73-84.
4. Yamada, S., Hill, M., Takakuwa, T., Human embryology, in New discoveries in embryology, B. Wu, Editor. 2015, intechopen.com. p. 97-123.
5. Markert, M., Ethical Aspects of Human Embryo Collections: A Historically Grounded Approach to the Blechschmidt Collection at the University of Gottingen. Cells Tissues Organs, 2020. 209(4-6): p. 189-199.
6. Blechschmidt, E., The stages of human development before birth. 1961: S. Karger, London, New York.
7. Gerrelli, D., et al., Enabling research with human embryonic and fetal tissue resources. Development, 2015. 142(18): p. 3073-6.