In June 1938, Pius XI summoned American Jesuit John LaFarge, who began to prepare a draft of Humani Generis Unitas, which LaFarge and two other Jesuits—Gustav Gundlach and Gustave Desbuquois—worked on in Paris; the draft was approximately 100 pages long. Another Jesuit translated the draft encyclical into Latin, presenting it to Vladimir Ledochowski, then the General of the Society of Jesus—who had chosen Gundlach and Desbuquois for the project. The draft encyclical was delivered to the Vatican in September 1938.