Harry Borrer Kirk was born at Coventry, Warwickshire, England, on 9 March 1859, one of nine children of Sarah Jane Mattocks and her husband, Thomas Kirk, a timber merchant's clerk who was to become well known in New Zealand as a botanist. With his parents and three siblings Harry came to New Zealand aboard the Gertrude, arriving at Auckland on 9 February 1863. He attended Auckland Grammar School from 1 May 1871 until late 1873. The family moved to Wellington in early 1874 following Thomas Kirk's appointment as professor of natural science at Wellington College and Harry continued his education there. He was a brilliant boy, an all-rounder, and gained scholarships and prizes in mathematics, English, modern languages, Classics and natural science. He enjoyed football and played for Wellington College against Nelson College in June 1876 in the first of a long series of intercollegiate matches.
As there was no university college in Wellington, after leaving school Kirk studied on his own for University of New Zealand examinations, securing his BA in 1882 and graduating MA with first-class honours in 1883. That year he joined the staff of the Department of Education as a clerk and in 1885 became the assistant inspector of native schools. For the next 17 or 18 years he travelled the length and breadth of New Zealand on horseback. He undertook his journeys of inspection in all weathers and often had to ford rivers to reach his destination. He was to blame the frequent soaking for the crippling arthritis which he suffered during the latter half of his life.
During his travels around New Zealand he increased his knowledge of the local flora and fauna by collecting many botanical specimens for himself and other naturalists. He also established a rapport with the people he met, both Maori and Pakeha, and acquired a fund of anecdotes and stories that would, in later years, embellish his lectures and delight his friends and students. Kirk possessed a dry sense of humour that was to help him immensely in the next phase of his career.
In February 1903 Kirk was appointed to the chair of biology, as foundation professor, at the fledgeling Victoria College in Wellington. There was some trepidation within the college council over the choice of Kirk for this position, as he had no academic teaching experience and was the only staff member educated in New Zealand. Kirk soon proved the decision in his favour to be sound. The college had yet to acquire premises, and classes were conducted in rooms at Wellington Girls’ High School in Thorndon and at the Wellington Technical School in Mercer Street. Kirk taught classes in a room near the Girls’ High School which was occupied during the day by Miss Baber's kindergarten, and which, therefore, he could use only at night. However, he entered into his new work with an enthusiasm that never waned during his 42 years at Victoria.
Kirk's life's ambition was the establishment and development of a biology department within the new university college, and he was unwavering in the pursuit of this goal. With the development of the 'old clay patch', as it was called, in Salamanca Road, Kelburn, he moved to a basement room in the first building, later known as the Hunter Building. Following the First World War Kirk's laboratories were established on the top floor of an extension to the building, where they remained until the erection of a biology building in 1939.
After the outbreak of war in 1914 Kirk proved that biology could be practical as well as academic by demonstrating how to deal with the fly menace that developed in the military camps, describing methods to combat the problem in a pamphlet. Kirk's research interests were wide-ranging and his 25 scientific publications covered a vast field, although his particular interest was sponges.
Kirk belonged to the New Zealand Institute (later the Royal Society of New Zealand) and was one of the original fellows, being elected in 1919. He was president of the Wellington Philosophical Society in 1907–8 and was president of the New Zealand Institute in 1922–23. In 1910 Kirk helped found the University Reform Association. At that time New Zealand university examinations were set and marked in Britain in the belief that this was the only way to ensure high standards. The association wanted an Australasian examination system to be set up instead. From 1915 to 1920 he was a member of the senate of the University of New Zealand, and from 1930 to 1944 a member of the academic board. He was chairman of the Committee of Management of the Dominion Museum in the late 1930s and early 1940s.
As a teacher Kirk inspired his students not just with a love of knowledge but also with respect for truth and integrity. He was remembered as a gentle, sincere and charming man, whose one objective was service to others. He was a trusted adviser and friend to many students. On 10 July 1885 at Dunedin Kirk had married Annie Lamont. After her death in 1927 he lived with his two daughters, Ethelwin Gladys and Hilda Gyneth.
The biology building that he had worked towards for so long was later named after Kirk. Past students and colleagues contributed towards the preparation of a bronze portrait plaque which was unveiled by H. G. R. Mason, minister of education, in the foyer of the building on 16 November 1940. When Kirk's original building was superseded in 1972 this plaque was removed and placed in the foyer of the new building.
In his devotion to university work Kirk worked long and hard, often well into the night. Many students can recall hearing the sound of his typewriter in the small hours. His health grew worse and his eyesight began to fail. He retired in 1944. While in Tauranga in 1948 he suffered a fracture of the leg and was transferred to Hamilton for an operation which, it turned out, could not be performed. He died at Waikato Hospital on 15 July.