A set of eleven plaster models mounted on narrow metal pillars set on square wooden bases. Each model represents a stage in the development of the frog embryo. In contrast with similar Mueller-Ward models, which are primarily painted brown, models of this type are brightly painted in contrasting colours. Several models have been repainted resulting in inconsistent pigments within the set.
It is unclear whether whether the models represent a complete set, or whether this set has been made up of a single set of models.
2023.zoo.80.1: This is a round model painted in four colours. This model has recently been repainted in bright pigments.
The following is written in pencil on a white adhesive label on the wooden base: “FROG// WHOLE// I A”
The following is written in black marker on the wooden base: “VII 6”
The metal Mueller-Ward label is missing from this model.
2023.zoo.80.2: A model generally consisting of a half-round exterior with a sphere nested within.
The following is written in black ink on the wooden base: “XI b”
The metal Mueller-Ward label is missing from this model.
2023.zoo.80.3: A half-round model with an oblong cavity on the upper part of its flat face. This model has a duller, more pastel pigmentation than other models in this set.
The following is written in pencil on a white adhesive label on the wooden base: “FROG I// CS”
The following is written in ink on the wooden base: “BIII”
The metal Mueller-Ward label is missing from this model.
2023.zoo.80.4: A longitudinal section, half-round model with two oblong cavities on its flat face, one larger than the other. This model has recently been repainted in bright pigments.
The following is written in pencil on a white adhesive label on the wooden base: “FROG II// LS”
This model retains its original metal Mueller-Ward label. The metal label includes a smaller white paper label upon which the following numeral is printed: “VIIIa// COPR. 1941”
A paper adhesive label on the front face of the wooden stand reads as follows in printed text: “Early Gastrula”
2023.zoo.80.5: A longitudinal section, half-round model with two oblong cavities on its flat face, one larger than the other. This model has recently been repainted in bright pigments.
The following is written in pencil on a white adhesive label on the wooden base: “FROG III// LS”
This model retains its original metal Mueller-Ward label. The metal label includes a smaller white paper label upon which the following numeral is printed: “BII// COPR. 1941”
A paper adhesive label on the front face of the wooden stand reads as follows in printed text: “Early-Mid Gastrula”
2023.zoo.80.6: A longitudinal section, half-round model with two oblong cavities on its flat face, one larger than the other. This model has recently been repainted in bright pigments.
The following is written in pencil on a white adhesive label on the wooden base: “FROG IV// LS”
This model retains its original metal Mueller-Ward label. The metal label includes a smaller white paper label upon which the following numeral is printed: “BIV// COPR. 1941”
A paper adhesive label on the front face of the wooden stand reads as follows in printed text: “Mid-Late Gastrula”
2023.zoo.80.7: A longitudinal section, half-round model with two oblong cavities on its flat face, one larger than the other. This model has recently been repainted in bright pigments.
The following is written in pencil on a white adhesive label on the wooden base: “FROG V// LS”
The following is written in black marker on the wooden base: “XIa”
The metal Mueller-Ward label is missing from this model.
A paper adhesive label on the front face of the wooden stand reads as follows in printed text: “Late Gastrula”
2023.zoo.80.8: A cross-sectional model with a rounded surface truncated by a flattened face. There is a divot in the upper part of the rounded surface. The flattened face has a single cavity.
The following is written in pencil on a white adhesive label on the wooden base: “FROG VI// XS”
This model retains its original metal Mueller-Ward label.
2023.zoo.80.9: A cross-sectional model with a rounded surface truncated by a flattened face. There is a divot in the upper part of the rounded surface, smaller than in 2023.zoo.80.8. The flattened face has a single cavity, smaller than in 2023.zoo.80.8.
The following is written in pencil on a white adhesive label on the wooden base: “FROG VII// XS”
The following is written in black marker on the wooden base: “XIII”
The metal Mueller-Ward label is missing from this model.
2023.zoo.80.10: A longitudinal section model curved surface truncated by a flattened face. This is the second most elongated model in the collection after 2023.zoo.80.11.
The following is written in pencil on a white adhesive label on the wooden base: “FROG VIII// LS”
The following is written in black marker on the wooden base: “XVa”
The metal Mueller-Ward label is missing from this model.
2023.zoo.80.11: A longitudinal section model curved surface truncated by a flattened face. This is the most elongated model in the collection. This model has recently been repainted in bright pigments.
The following is written in black marker on the wooden base: “XVIII”
This model retains its original metal Mueller-Ward label. The metal label includes a smaller white paper label upon which the following numeral is printed: “XVIIIa// COPR. 1941”
Accession Number: 2023.zoo.80.1-11
Alternative Name:
Primary Materials: Plaster, Wood.
Markings of individual models are noted in the description field.
Dimensions of the square base= 10 x 10. Typical height of a model is ~14. The longest model is 26.
These models represent the stages of embryological development of the frog, an organism commonly used in biological instruction. These examples use abstracted colours to show features of the developing embryo.
A c. 1945 Mueller-Ward catalogue notes the following: “The models are not meant to supplant the actual study of the frog’s egg itself, but only to give the student certain definite ideas and a few clear landmarks so that this study may be rendered easier and more profitable.”
The paint of most of the models has been chipped with use, especially around exposed edges. A few have recently been repainted as of March 2023. 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). As of February 2023, several have been repainted in preparation for an exhibit at the Department of Ecology & Evolutionary Biology (EEB).
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 two sets catalogued here (2023.zoo.80.1-11 and 2023.zoo.81.1-7) may be incomplete.
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. See especially Mueller-Ward models of frog embryology (c1945). (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).
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.