 In the early decades in the twentieth century biochemists and cytologists developed their own research techniques and pursued their investigations independently of the other. Most biochemists implicitly embraced the assumption that the cell was a bag of chemicals that could be studied in the extracts remaining after cell structure was destroyed whereas those pursuing cytological inquiries tended to embrace the factory metaphor in which organelles were distinct machines. As witnessed by Cowdry’s (1924) General Cytology and Bourne’s (1942) Cytology and Cell Physiology, there were researchers who desired to build bridges between biochemistry and cytology. There were some techniques, albeit limited, for determining the chemical composition of organelles (essentially, those of cytochemistry and histochemistry, which relied on determining to which chemicals various stains bound). The nearly simultaneous introduction of cell fractionation and electron microscopy in the late 1940s provided the needed research techniques and, as noted in  Section 1,  helped establish modern cell biology (Bechtel 2006; Matlin 2018). In addition to the linkage of microsomes to the endoplasmic reticulum, described above, researchers linked oxidative metabolism to the inner membrane of the mitochondrion. New structures were also discovered and connected to functions, such as the lysosome which was linked to the breakdown and recycling of disrupted cell components (de Duve 1958).