Doctor Dolittle and the Green Canary (1950)-- Secret Lake was really the last Dolittle book, both in terms of composition and in terms of the internal chronology of the stories. Nevertheless, two additional Dolittle books were published after Hugh Lofting's death. The first, Doctor Dolittle and the Green Canary, draws on some material that had appeared in serial form in the New York Herald Tribune in the mid-1920's: specifically, stories of Pipinella, the canary whose sung "autobiography" formed a good portion of Doctor Dolittle's Caravan. Lofting had worked on expanding her story and further adventures into its own book; his sister-in-law and editor, Olga Fricker, assembled his notes and finished the task.
More to come...