
"The action of carbonate of ammonia on chlorophyll-bodies" Journal of the Linnean Society of London (Botany) (read 6 March 1882) volume 19, pages 262-284, at page 262 http://darwin-online.org.uk/content/frameset?pageseq=1&itemID=F1801&viewtype=text
Detractors sometimes claim Darwin thought that the cell was an undifferentiated mass of protoplasm. Anyone reading this paper will realize that Darwin thought no such thing.
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