Extensive drafts from a box inscribed 'Ms.Book / The Cell / 1954 / unpublished' sometimes referred to as 'Experimental cytology'.

Draft contents list (4 pages), heavily revised and corrected. This envisages 'Part I Structure' (Chapters 1-8), 'Part II Genetics' (Chapters 9-14), 'Part III Mechanics and Physiology' (Chapters 15-18). The various manuscript and typescript drafts conform approximately to this plan, though Darlington gave the same title, 'Structural hybridity' to both Chapters 8 and 9.