During WWI Northcroft served in the
New Zealand Expeditionary Force receiving the
British War Medal. His occupation at enlistment was law clerk. He then lectured in biology at Otago before gaining a Ph.D. at
Victoria University College in
Wellington in 1931. Between 1923 and 1929, he worked on the biology of the blackberry publishing five papers and wool fibres publishing one paper. In 1949, he returned to
Dunedin where he became a general practitioner and instructor at the
Otago medical school. == Personal life ==