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Models of Chick Embryological Development (Mueller Ward)


A set of eleven plaster models mounted on narrow metal pillars set on circular wooden bases. Each model represents a stage in the development of the chicken embryo. The models are brightly painted in contrasting colours.

This set is similar to 2023.zoo.85.1-6, which is catalogued in detail.

It is unclear whether the models represent a complete set, or whether this set has been made up of a single set of models. The set is likely complete as two additional sets of this kind contain the same number of models. This set is similar to two similar sets, 2023.zoo.85.1-6 and 2023.zoo.86.1-6, but the models are set on circular rather than square bases.

Accession Number: 2023.zoo.87.1-6

Alternative Name:

Primary Materials: Plaster, Wood.


Dimensions (cm):

Dimensions of the square base= 10 x 10, Maximum width of these models is 15. Maximum height is 23.


These models represent the stages of development of the chicken embryo, an organism commonly used in biological instruction.


The paint of most of the models has been chipped with use, especially around exposed edges. It is not clear whether this set is complete.

Associated Instruments:


Ward’s Natural Science Establishment, Inc., Rochester, NY.

Date of Manufacture: Mid 20th Century.


These models were used at the Department of Zoology (now part of the Department of Ecology & Evolutionary Biology and the Department of Cell & Systems Biology).

The models were photographed and catalogued on Feb 6, 2023. They remain at the Department of Ecology & Evolutionary Biology.

Additional models of this type are located in the EEB teaching lab, so the sets catalogued here may be incomplete.

Additional Information and References:

A brief biography of Justus F. Mueller (1902-1993), the developer of the models, can be found at New York Heritage Digital Collections, along with information on his personal papers at SUNY Upstate Medical University – Health Sciences Library. (Archived February 13, 2023).

Some relevant digitized catalogues can be found at “The Ward Project” website that is run by the University of Rochester. (Accessed March 7, 2023)

A brief history of Ward’s Natural Science Establishment, Inc., which produced the models, can be found at the River Campus Libraries of the University of Rochester. This archive holds the company’s papers. (Archived February 13, 2023).

Historical Notes:

The models in this collection were developed by Justus F. Mueller (1902-1993), an American parasitologist educated in both art and zoology. Following his graduate research at the University of Illinois, Mueller took a position at the New York State College of Forestry (now SUNY College of Environmental Science and Forestry) in Syracuse, New York in 1929. While at the College of Forestry, he partnered with Ward’s Natural Science Establishment, Inc. to create 16 sets of zoological models comprising 116 models.

Ward’s Natural Science Establishment was founded in 1862 by Henry Augustus Ward (1834-1906). The company supplied natural science materials to museums. In 1928, the Ward family donated the company to the University of Rochester. The company began to flourish in the 1940s and was sold to Dean L. Gamble, its president, and Frank Hawley Ward in 1940. The company became very successful during the expansion of science education in the early Cold War Period.