In 1918, on the passing of the new Scottish Education Act, he was selected as Director of Education for Moray, and when the administration of Moray and Nairn was combined in 1932 he was continued as Director of the joint county until his retiral on reaching the age-limit in the following year. Throughout this period of specialized teaching and educational administration his common-sense and sound views on educational policy won the confidence alike of the authorities and the teachers. Yet during the greater part of this period another consuming interest claimed Dr McIntosh's activity.
Stimulated during his M.A. course by Professor Alleyne Nicholson's lectures on Natural History he turned to marine zoology, and in order to add to his qualifications he commenced to work for the newly instituted B.Sc. degree at Aberdeen University; this he obtained in 1906. When opportunity offered he spent his vacations in study: once at Columbia University, New York; on several occasions at Millport Marine Station on the Clyde where he concentrated on Echinoderms, dredging his material from S.Y. Mermaid and making use of his mathematical knowledge in statistical analyses of variations in a selected star-fish and brittle-star; and frequently on the Scottish Fishery Board Research Steamer Goldseeker, again mainly for the collecting of Echinoderms.
As a result he named the considerable collection of Echinoderms dredged by the scientific staff of the Fishery Board, published several papers on variation, in Biometrika, Proc. Roy. Phys. Soc. Edin. and Proc. ZooL Soc. Lond., and described the Ophiuroidea of the Mergui Archipelago in the Indian Ocean, collected in 1907 by Dr J J Simpson and Dr R N Rudmose Brown, amongst which he found a species new to science. For a thesis "Studies on Echinodermata and on Variation" he was awarded the degree of D.Sc. by Aberdeen University in 1912.
During his Edinburgh years he was a regular attender at the meetings of the Mathematical, Royal Physical and Royal Societies of Edinburgh. After his retiral in 1933 he settled at Boat of Garten and continued to serve in many ways - on Inverness County Council and its Education Committee, on the Badenoch District Council, as Session Clerk to St Columba's Church, and as a justice of the Peace for Moray and Nairn. Dr McIntosh was a willing worker and good friend and all he did was done with thoroughness and imperturbable good humour.
He was elected a Fellow of this Society in 1903, and died, on July 1, 1957, in his ninetieth year, survived by his wife.