After matriculating from the King's School in Parramatta, Launcelot Harrison worked for Citizen's Life Assurance Company and played Rugby for New South Wales in 1901. He married Amy Eleanor Mack in 1908 in North Sydney, and enrolled in a Bachelor of Science at the University of Sydney in 1911, to develop his keen interest in the natural world.
In 1914, Harrison graduated with first class honours and the University medal in Zoology. He then tutored at the university and won a scholarship for postgraduate work. Interrupting his further studies, he joined the British Expeditionary Force in Mesopotamia in the rank of lieutenant, working as an advising entomologist. Despite contracting typhus and malaria, he was able to use his expertise to save the lives of many people.
In 1918, Harrison was made a lecturer at the University of Sydney. He returned from active service the following year to take up the position, and was rapidly promoted, becoming Professor of Zoology in 1922. Harrison was a respected teacher and researcher, and active in the intellectual community.
In addition to his zoological publications and work in related fields, Harrison also wrote children's poetry and fiction, and illustrated much of it himself.
After his death, the Harrison Memorial Fund was established. Interest from the fund is used to purchase zoology books which comprise the Harrison Memorial Collection at the University of Sydney.
