Published in 1921 by the University of Toronto Press, University of Toronto Roll of Service 1914-1918, is an uncommon find in the first edition, but fairly easy to find at larger public and institutional libraries.
The entire text is also available to download via the internet archive, and can be found here. Peregrine Acland’s entry is on page 169. I’ll include it below.
At 603 pages, one is struck by the sheer volume of service. There must be 8,000 names of men associated, not with the city of Toronto, but with the university. This included the fallen, those who returned, and those that enrolled immediately after service.
The introduction of the text details the actions of the university during the war, (which included rehabilitating soldiers returned from the front and no longer fit for service) and on pages page xxiv-v Acland is mentioned under the section heading Military Instructors in the Colleges of the United States.
When the United States entered the war, a demand came from the Colleges for military instructors from Canada who had seen service overseas. From this University were sent some who had been invalided home, whose experience at the front combined with their academic training especially fitted them for this work. These were: …Major P. P. Acland, M.C., to the Washington State College and Groton School, Mass. …
As a side note: amongst the others seconded to American academic institutions was Lieut. Raymond Massey, who instructed at Princeton and Yale, before he was sent on the Siberian expedition in 1918. Another Canadian writer of the First World War, W. Redvers Dent, was on the same expedition as a machine gun instructor.