Voluntary cadet groups had existed prior to the passage of the 1909 Defence Act. Here School cadets from Wellesley Street Normal School in Auckland, can be seen in uniform complete with rifles, drums, and a pug dog (mascot?).
This photo was taken by an unidentified Auckland Star photographer in 1900, during the South African (Boer) War. Chances are many of these young boys served in the First World War.