New Zealanders and Science
11 — Cockayne
It is natural that New Zealanders should show a more intimate appreciation of those scientists whose work is visibly influenced by New Zealand associations than of those who achieved their successes abroad. In the truest sense they are New Zealand scientists whose work bears the impress of our land and sea, and, more subtly, the impress of our modes of thought. Yet, curiously enough, the three men, Cotton, Guthrie-Smith, and Cockayne, who are par excellence New Zealand scientists in this sense, were born outside the Dominion. Cotton found his inspiration in the diverse contours of the New Zealand landscape. Guthrie-Smith settled on a sheep run north of Napier fifty years ago, studied the changes in plant-growth brought about by European settlement —changes as minute and gradual as those of an hourglass, but quite as inexorable—and in Tutira gave to the world the story of his observations in this new and fascinating branch of ecological botany. Cockayne, the subject of this chapter, coming to New Zealand page 118in search of health, found here a unique field for botanical research.
Leonard Cockayne was born at Norton Lees, a Derbyshire village, on 7 April 1855. He developed a bent for natural history, and after leaving school his desire for scientific learning led him to Owen's College, Manchester. Like Owen, Huxley, and Hector, he found that the only access to university study in science at that time, 1873, was through the medical course. Although a brilliant youth, he did not take kindly to the prescribed courses of study and did not persevere with the degree. Moreover his health broke down, and he left England in 1879, going first to Australia and then on to New Zealand in 1881. Until 1885 he was a teacher at Greytown (now called Allanton) in the Taieri plains. Then, obtaining an income sufficient for his wants, he was able to retire and to devote his life to the study of the native flora of New Zealand. He established a private experimental station on four and a-half acres of sandy soil at New Brighton, near Christchurch, and there he introduced a large number of shrubs and trees and carried out experiments in sand dune reclamation. In his garden he was able to study the seedling development of many New Zealand plants and the variations in form during development that are one of their most striking features. To quote his own words, 'for various reasons the plant life of New Zealand is of peculiar interest, especially its extreme page 119isolation from other land-masses, its flora of diverse origin but with an astonishing number of endemic species and group after group of wild hybrids, the numerous and often peculiar life-forms of its members, its having developed unmolested by grazing and browsing mammals, and its vegetation, so diversified that only a continent extending into the tropics can claim an equality.'
Cockayne studied the plant in all its varied environments with a view to learning how and why the variations in soil, climatic conditions, and association with other nearby plants affected its mode of growth and modified its form. The importance of such study to the problems of plant evolution generally is obvious. For Cockayne was studying the origins of species in plant-life, thus specialising in a section of the Darwinian field.
Realising the wide scope of his subject, Cockayne did not restrict his study in plant variation to New Zealand only, but corresponded with botanists in many parts of the world, exchanging specimens with them. In this way he was able to introduce to Christchurch gardens many valuable species, besides supplying himself with rich material for the comparative study of plant-forms. He devoted his energies to a branch of botany which had so far received scant investigation. As Sir Arthur Hill wrote in the obituary notice published by the Royal Society: 'Unrecognised and unlabelled at first, Cockayne was already an page 120ecologist waiting for the term to be adopted by botanists, and fully trained, with his keen insight, to lead the way not in New Zealand only but in the world.'
A great stimulus to Cockayne's botanical career was the visit to New Zealand in 1898 of von Goebel. Karl Ritter von Goebel was then the acknowledged leader of European botany and a pioneer of the new ecological study. He saw New Zealand's wealth of vegetation under Cockayne's guidance, and he was much impressed by Cockayne's work, particularly his study of plant morphology in the New Brighton garden. The two men became firm friends, and in 1903 von Goebel was instrumental in having the honorary degree of doctor of philosophy conferred on Cockayne by the University of Munich.
Very early in New Zealand's botanical history the elder Travers had noted the occurrence of natural and wild hybridisation and had reported the fact to Darwin as one of considerable importance to the theory of evolution. Cockayne's study of the reactions of plants to environment especially in the early stages of their growth, and later his intensive study of hybrids, led him to modify Darwin's theory of natural selection. Adaptation to changing environment was not the only factor in the variability of species. Hybridisation was also a factor and a very significant one. With the assistance of his greatest follower, Dr H. H. Allan, Cockayne established the existence of at least 491 groups of natural hybrids in New Zealand, of which six were actually intergeneric crosses, that is, crosses between closely related forms. page 122This extraordinary success in a research extending over thirty years was the result of patient and untiring work in field and garden, and of strenuous journeys in many parts of New Zealand and in outlying groups of islands. Of his lovable qualities as a travelling companion Sir Arthur Hill, the famous English botanist, wrote after an excursion with Dr Cockayne and his son Alfred*: 'He was at times a trifle disturbed by a sudden change of plan and had a facility for losing his cap or his bag, but his sense of humour always saved the situation and we had a great time together. No matter whether we were in a crowded train or wedged in the back seat of a motor car, he would discuss abstruse botanical matters or bring forward knotty points as to hybrids, or what was meant by such and such a species. Then his son Alfred would join in with a totally opposite point of view and a fierce altercation, proving quite harmless, would ensue—an outsider might have thought blows would follow!—and all would end happily.'
As a result of the activity of Cockayne and his followers, New Zealand hybrids have probably been studied more thoroughly than those of any other country. Cockayne realised that solutions to problems of plant evolution as exemplified in the New Zealand flora would apply not to this country alone, but mutatis mutandis to the rest of the world. The full extent of his work on botanical nomenclature and page 123classification cannot yet be realised, but his investigations and those of men like von Goebel, de Vries, and Sir Arthur Hill are effecting a revolution in botanical science and a complete revision of the older systems of classification.
Cockayne's work soon earned him a world-wide reputation. As early as 1904 he was requested to write the New Zealand volume for Die Vegetation der Erde, a comprehensive survey of botanical research in all parts of the world. The war delayed the publication of this work until 1921, a second edition appearing in 1928. His volume in this series was regarded by Cockayne as his masterpiece. In it he traced the history of botanical research in New Zealand and treated in great detail the vegetation which covers this country and the islands once connected with it.
Many honours were bestowed upon him. He became an f.l.s. in 1910 and an f.r.s. in 1912. He was a corresponding member of many foreign societies, and had many doctorates conferred upon him. He gained all the available local distinctions, including the first Hector medal in 1912 and the Hutton medal in 1914. He was an original Fellow of the New Zealand Institute and its president in 1918-9. His greatest honour was the Darwin medal of the Royal Society awarded to him in 1928. This, the world's highest honour in biological science, is presented every second year without distinction of race or sex to the most distinguished workers in the page 124Darwinian field. Dr Cockayne's was the twentieth name in this list, the first from the southern hemisphere, and one that brought as much honour to the list as it received. By a happy coincidence Sir Ernest Rutherford was president of the Royal Society the year of Cockayne's award, and it was indeed a proud moment for this country when one of the world's greatest physicists, a New Zealander who had taken his place as a leader in the centre of the scientific world, made the dedicatory speech to honour one of the world's greatest ecologists, a botanist living and working in the same far-off New Zealand.
Cockayne, who was almost totally blind in his last years, died at Wellington on 8 July 1934. He was buried in the Otari Open Air Museum, a botanical reserve established by him near his Ngaio home.
* Now Director-General of Agriculture.