Possums is a 174-page book consisting of a series of essays written about the Virginia opossum (Didelphis virginiana), the only living marsupial in the US. The essays were written by Carl Gottfried Hartman, an embryologist at the Carnegie Institute of Washington (CIW), in Baltimore, Maryland, who also worked with another mammal, the rhesus monkey. Possums was published in 1952 by Hartman's alma mater, the University of Texas at Austin (UT). Beginning in 1913, while as a graduate student, and later as an instructor at UT, Hartman captured and raised opossums. He was one of the first zoologists to study the intricacies of opossum embryology, leading to an account of the embryology and reproductive physiology of a mammal from the wild, rather than of a mammal bred exclusively for laboratory research. Possums culminated Hartman's studies of the marsupial.

Benjamin Harrison Willier is considered one of the most versatile embryologists to have ever practiced in the US. His research spanned most of the twentieth century, a time when the field of embryology evolved from being a purely descriptive pursuit to one of experimental research, to that of incorporating molecular biology into the research lab. Willier was born on 2 November 1890 near Weston, Ohio to Mary Alice Ricard. He spent his childhood doing farming chores and running the farm while his father, David Willier worked as a banker. Willier graduated from high school with no immediate desire to attend college; his goal was to become a public school teacher. After a year of special study he was certified to teach. But this desire took a turn when his cousin and public school teacher, Alice Ricard, convinced him to attend a six-week summer session of the State Normal College of Miami University (Ohio). It was here that Willier was introduced to nature study and where he made his decision to pursue a scholarly life.

Rachel L. Carson studied biology at Johns Hopkins University in Maryland and graduated in 1933 with an MA upon the completion of her thesis, The Development of the Pronephros during the Embryonic and Early Larval Life of the Catfish (Ictalurus punctatus). The research that Carson conducted for this thesis project grounded many of the claims and observations she presented in her 1962 book, Silent Spring. This book focused on the environmental dangers of using pesticides against insects and plants deemed invasive, and it received attention from the US government, to such an extent that Carson testified before US congress in Washington D.C., and US President John F. Kennedy appointed a commission to validate her claims.

Felix Anton Dohrn is best remembered as the founder of the Stazione Zoologica di Napoli, the world' s first permanent laboratory devoted to the study of marine organisms. Dohrn was born on 29 December 1840 in Stettin, Pomerania (now Poland), to a wealthy merchant family. Dohrn's paternal grandfather, Heinrich, trained as a surgeon and then established a sugar refinery, while Dohrn's father, Carl August Dohrn, who inherited the family business, became interested in natural history through Alexander von Humboldt, a family friend. Once settled in his career, Anton Dohrn's own research never strayed far from the origin of vertebrates. He promoted the theory that vertebrates closely resemble and are derived from annelid-like ancestors and he spent years studying the early embryogenesis of lower vertebrates in attempts to prove this.

Embryos in Wax: Models from the Ziegler Studio is a history of embryo wax modeling written by science historian Nick Hopwood. Published by the Whipple Museum of the History of Science University of Cambridge and the Institute of the History of Medicine University of Bern, 2002, the book, like the wax models, helps exemplify the visual and material culture of science. The first half of the book describes the modeling work of Germany's Adolf and son Friedrich Ziegler during the rise of developmental embryology from 1850 to 1920, a time when embryology's practitioners needed educational aids that could help teach students in laboratories and lay persons in public lectures. Three-dimensional wax models provided just this visual aid.

Three-dimensional anatomical models have long been essential to the learning of science and lend a sense of "control" to those practicing in the field. As the development of embryology grew in importance during the late 1800s, so did the need for models to show intricate details of embryos. Embryologists such as Wilhelm His, Ernst Haeckel, and Oscar Hertwig all initially constructed their own wax models of embryos but later handed over the modification and reproduction of their models to various "plastic artists." The most renowned among these artists was Adolf Ziegler.

Sand dollars are common marine invertebrates in the phylum Echinodermata and share the same class (Echinoidea) as sea urchins. They have served as model laboratory organisms for such embryologists as Frank Rattray Lillie and Ernest Everett Just. Both Lillie and Just used Echinarachnius parma for their studies of egg cell membranes and embryo development at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, in the early 1900s. More recently, William Eugene Berg at the University of California, Berkeley, used Dendraster excentricus, a sand dollar common to the Pacific Coast of the US, to help pioneer the mid-twentieth-century studies of protein synthesis in embryos. Sand dollars are also easy to work with in the classroom, serving as model organisms for the study of fertilization and development.

The scientific field of embryology experienced great growth in scope and direction in Germany from approximately 1850 to 1920. During this time, Adolf Ziegler and his son Friedrich crafted hundreds of wax embryo models, representing a shift in how embryos were viewed and used. Their final products, whether human or trout embryos, showcased the now lost collaboration between wax modeling artists and embryologists.

Ernst Heinrich Philipp August Haeckel was a prominent comparative anatomist and active lecturer in the late nineteenth and early twentieth centuries. He is most well known for his descriptions of phylogenetic trees, studies of radiolarians, and illustrations of vertebrate embryos to support his biogenetic law and Darwin's work with evolution. Haeckel aggressively argued that the development of an embryo repeats or recapitulates the progressive stages of lower life forms and that by studying embryonic development one could thus study the evolutionary history of life on earth.

To Lynn M. Morgan, the Mary E. Woolley Professor of Anthropology at Mt. Holyoke College, nothing says life more than a dead embryo. In her easily readable book, Icons of Life: A Cultural History of Human Embryos, Morgan brings together cultural phenomena, ethics, and embryology to show that even dead embryos and fetuses have their own stories to tell. As an anthropologist, Morgan is interested in many things, including the science of embryology and its history. But she also wants to know how culture influences our views on embryos and the material practices that accompany their study. Her intent is to establish a relationship between specimens collected in the remote past and the contemporary cultural politics of abortion (p. xiii). The eight chapters in Icons of Life do not provide an exhaustive historical look at early American embryology, but they do weave together the Carnegie Institute of Washington Embryology Department (CIWED), its major human embryo collector Franklin Paine Mall, and how early twentieth-century science worked. Morgan ably describes the CIWEDÕs early foray into embryo collecting, but she wants to do more than just describe how embryos made their way to the laboratory. She wants us to ask why it was even possible for such a thing to happen without so much as a fuss being made from the public. This involves looking at culture.

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