Marshall's "Trees" and the Global "Forest": Were "Giant Redwoods" Different?

Leslie Hannah, Learning by Doing in Markets, Firms, and Countries (University of Chicago Press, 1999), chap. 7, https://www.nber.org/books-and-chapters/learning-doing-markets-firms-and-countries/marshalls-trees-and-global-forest-were-giant-redwoods-different.