The MCZ models were purchased in the 1870s and 1880s from Leopold and Rudolf Blaschka, father and son glass workers. From their studio in Dresden, Germany, the Blaschkas supplied museums and universities with life-like and scientifically accurate models, available for direct purchase or through catalogs. A majority of the models were acquired through the Blaschkas' North American distributor, Henry Ward. Published in 1878, the Catalogue of Glass Models of Invertebrate Animals from H. A. Ward's Natural Science Establishment offered 630 invertebrates, ranging from $0.30 to $6.50.
In the late 1880s, the Blaschkas began making botanical models for the Harvard Botanical Museum and in 1890 they entered into an exclusive, ten-year contract with Harvard to create glass models of flowers and plants. Through subsequent contract extensions, Leopold and Rudolf made botanical models for Harvard for the remainder of their careers, never returning to zoological models.
A vast majority of the models are made solely of glass (colorless and colored) and water-soluble pigments for life-like coloring. Some are also constructed with organic materials, such as glues and stretched animal hide, and occasional pieces of wire for support and texture.
For decades, the MCZ's Blaschka glass invertebrates were stored in the relevant departmental collection by taxa, as their primary and original use was for teaching and morphological comparison. Around 1900, the glass invertebrates were removed from their original cardboard trays and mounted with wire to white plaster plates, as they remain today.
The models have recently been recurated as a cohesive collection in the MCZ, including a major initiative to clean and repair all of the models. Most of the damage to the models is minor and due to the failure of the original 19th century glue used in their construction. Faulty contact points are restored with reversible, archival adhesive.
In May 2014, a new permanent exhibition of the MCZ’s Blaschka glass invertebrate models opened at the adjacent Harvard Museum of Natural History. Sea Creatures in Glass showcases a rotating selection of approximately 60 of the models in the MCZ’s collection.