In the period of “classical genetics” (roughly 1915–1950), the common view of the gene was mechanistic—that is, genes were seen as individual, atomistic units, as material components of the chromosomes. Although it was recognized early on that genes could interact and influence each other’s expression, they were still regarded as individually functioning units, much like the chemists’ atoms or molecules. Although geneticists in particular knew the story was more complex, the atomistic gene remained the central view for a variety of reasons. It fit the growing philosophy of mechanistic materialism in the life sciences, as biologists tried to make their field more quantitative, rigorous, and predictive, like physics and chemistry. Conceptually and pedagogically, it provided a simple way to depict genes (as beads on a string) that fit with the exciting new work on chromosomal mapping. The atomistic gene also fit well with the increasing drive to move capital into agriculture, both for potential patenting purposes and for ease of experimental manipulation and prediction. It is the latter point that the present essay explores most thoroughly. The rise of agriculture as an industrialized process provided a context and material support that fueled much of the rapid growth of genetics in the first half of the 20th century.