"Beatrice Mintz, known as “Bea” to her friends, was a developmental geneticist. ... Her pioneering work had a major impact on many different areas of science. She began her career addressing one of the most complex and fascinating questions of development: how the many different and diverse tissues in an organism are initiated and develop from a single fertilized egg. In the early 1960s Bea—at about the same time as in Poland and in Philadelphia—generated the first chimeric mice by combining early, genetically distinct, mouse embryos. She had contemplated this experiment for many years at the and began to work seriously on it after moving to (discussing the project with her colleagues) … And indeed, this manipulation of embryos was a breakthrough to a new era of experimental work in mammalian development. (Bea did not like the designation “chimera” because of its association with “monsters” in Greek mythology; she described these mice as “allophenic.”)"