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Johannes Holtfreter Papers

Identifier: MC-MBL-Holtfreter.

Scope and Contents of the Collection

This collection documents the professional life of Johannes Holtfreter who was a prominent developmental biologist in the mid-1900s. This collection includes both handwritten and typed letters with colleagues and students, newspaper clippings, lecture announcement posters, handwritten experiment notes, embryo experiment sketches, notebooks, travel documents, projectors, and 44 rolls of 16mm movie film. The collection follows various activities within Dr. Holtfreter’s career, including his numerous achievements within the field of embryology, his invitations to join various professional societies, as well as his friendship and collaboration with fellow embryologist Viktor Hamburger. Records within the collection date back to the early 1920s during his time in Germany before World War II, and follow his career and retirement until his death in 1992.

The Correspondence Series of this collection documents Johannes’ time in Germany, his two-year stent within the Canadian Internment Camps, and his academic professorship at the University of Rochester in the United States. The records also include biographical information, travel documents, letters written during trips and sabbatical appointments, lecture announcements, professional invitations, citizenship correspondence, consultations, appointments, criticisms, colleague letters, and correspondence with family and friends. Prominent holdings within this collection are the numerous letters of correspondence between Johannes and fellow embryologist Viktor Hamburger, as well as experiment notes and illustrations that focus on amphibian embryos and Spemann-Mangold’s Organizer.


  • 1923-1992

Language of Materials

Collection materials are in English and German, with a few documents in Japanese

Access Restrictions

Open: materials are available for research

Biographical History

Johannes Holtfreter was a 20th Century German-American developmental biologist who was famous for his work in the subject of embryology, specifically for his work with amphibian embryos. In the midst of his early career, World War II tensions were rising, and knowing he was being spied upon and fearing he would be caught by the Nazi regime, Johannes escaped to England. Once in England, he, along with other German refugees, were sent to Canada to an Internment Camp in order to escape the inevitable Nazi invasion in England. In 1942, after two long years in a Canadian Internment Camp, Johannes received a fellowship at McGill University in Canada which allowed him to continue his studies within the field of embryology, particularly on the subject of gastrulation in cells. After his time at McGill University, Johannes accepted an assistant professorship at the University of Rochester where he finished out his career as an associate professor in 1969.

Johannes Holtfreter is most known for his work in developing a salt solution, called Holtfreter’s Medium (or Holtfreter’s Solution) that helped to keep developing amphibian embryos alive and healthy while under scientific observation. As part of implementing the use of this salt solution, Holtfreter created best practice procedures for handling embryos under observation, which helped to reduce cases of bacterial contamination that were common at the time. He is also well-known for his studies of dead organizer tissue in relation to its inductive properties, which included applying Spemann-Mangold’s Organizer, which focused on cells that are responsible for the development of the nervous system within amphibian embryos. His focus on amphibian development resulted in collaborations with prominent scientists in the field, including Viktor Hamburger, Hans Spemann, and Hilde Mangold, and resulted in his induction into the National Academy of Sciences.


16 linear ft.


The materials within The Johannes Holtfreter Papers are from the professional life of Johannes Holtfreter, who was a prominent developmental embryologist in the mid-1900s. Within the collection are series of correspondence, experiment notes, experiment illustrations, photographs, and movie film. This collection documents Dr. Holtfreter’s work with the Spemann-Mangold’s Organizer, his work with amphibian embryo development, and his collaborations with fellow embryologist Viktor Hamburger.

Arrangement of the Collection

The entire collection was intellectually arranged and labelled into series and subseries by Dr. Holtfreter based on the type of document it was and by the date the document was written and/or received. In order to retain the series and subseries that were assigned by the creator, the materials have been kept within their original order within the folder level, which is for the most part in chronological order. The folders within the Correspondence Series have been arranged chronologically from oldest to newest based on the starting date of each folder’s date range. The original folder titles have also been retained. The material within each file is organized in original order based on when it was received and/or written during the time frame listed by the creator on the folder. The exception to the arrangement listed above are the files of correspondence that Dr. Holtfreter had with his more high-profile colleagues, such as Viktor Hamburger, which are separated into folders based on the correspondent. The materials within these folders have also been left in their original order within the folder level.

Acquisition Information

It is known that Hiroko Ban-Holtfreter, Johannes' wife, transferred her husband’s collection to the Marine Biological Laboratory around the year 2008.

Related Material

The library also has possession of the papers of Viktor Hamburger, who was a close friend and colleague of Dr. Holtfreter, as well as several publications by Viktor Hamburger on the subject of embryology. The majority of the correspondence between the two embryologists is documented within the Correspondence Series of The Johannes Holtfreter Papers, as well as within the Papers of Viktor Hamburger.

Papers of Viktor Hamburger 1900-2001 Hamburger, Viktor 11.33 linear ft. (8 Boxes) Mixed Material: correspondence, course lecture notes, meeting notes, writings, and illustrations. MBL- Rare Book Room Annex (non-circulating)

Collected Reprints of Viktor Hamburger Hamburger, Viktor 1925-1995, Volumes 1-5 Offsite Library Service Center

A Manual of Experimental Embryology Hamburger, Viktor Revised Edition, University of Chicago Press, 1960 Offsite Library Service Center QL957.H24 1960

The Heritage of Experimental Embryology: Hans Spemann and the Organizer Hamburger, Viktor New York: Oxford University Press, 1988 Offsite Library Service Center QL961.H34 1988

Separated Material

The library already owns a collection of Johannes Holtfreter’s reprints that range from 1919 to 1991. This collection is located within the MBL Rare Book Room and is housed within 10 volumes.

Collected Reprints of Johannes Holtfreter Holtfreter, Johannes 1919-1991, Volumes 1-10 MBL- Rare Book Room Q113.H64

Processing Information

At this time, only the Correspondence Series within this collection has been processed. The other series, which includes Illustrations/Notes, Experiment Notes, Photographs, Reprints, and Videos/Projectors, will be processed at a later date. Processing the remaining series within the collection will require assistance by a scientist, or science historian, with expertise in the field of embryology.

Johannes Holtfreter Papers
An inventory of his papers
Rebecca Corlett
13 Apr 2019
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Repository Details

Part of the Marine Biological Laboratory Archives Repository