NA TURE 



[June 27, 1901 



and energy. He had often complained of ill health. 

 Cut nothing in his appearance had ever suggested to me 

 ground for serious an.xiety. I had hoped to have induced 

 4iim to pay us a visit this year. I could not go to his 

 ■funeral ; nothing remains but the sad satisfaction of 

 writing these lines to his memory. 



Cornu was bom July i6, 1843, at Orleans. The ability 

 which he displayed in his schooldays seemed at first 

 likely to be absorbed by studies on the literary side. 

 But under the influence of his father and of his dis- 

 dnguished brother, Alfred Cornu, he devoted himself to 

 mathematics, and with considerable success. He pub- 

 ilished in the NoitveUes Aiuiales de MatluUitatiques 

 papers on geometrical subjects. In my judgment there 

 could be no better preparation for a scientific career. 

 Mathematics, as they are taught in France, habituate 

 the mind to the grasp of general ideas and accustom it 

 to rise from isolated facts to large generalisations. The 

 •descriptive side of science, it cannot be doubted, has a 

 •cramping influence, and it is the fate of too many of 

 those who devote themselves to it to be unable 

 ■" to see the wood for the trees." Cornu's mathematical 

 •studies, at any, rate, decided him for a scientific career, 

 and at the " Ecole normale superieure " he eventually 

 ifixed on botany. He was for a time assistant to Duchartre, 

 .professor at the Sorbonne, a man remarkable in many 

 ■ways, but possessing in a more than ordinary degree the 

 ipower of presenting with French lucidity the results of 

 ■current research, not forgetting those of English workers. 

 While with Duchartre, Cornu produced in 1S73, as his 

 "doctoral thesis, his well-known memoir on the Sapro- 

 ■legniace-iT?, to which the Academie des Sciences awarded 

 ■the Desmazieres prize. From the Sorbonne he moved to 

 the Museum as aidenaturalisle to Brongniart, whose 

 ■daughter he afterwards married. Brongniart brought 

 •down to our own day the best traditions of that illustrious 

 school of French botanists whose philosophic insight into 

 the principles of plant morphology and taxonomy has 

 probably never been rivalled, and certainly not surpassed. 



Under Brongniart, Cornu devoted himself to mycology. 

 He published in a comparatively brief period a profusion 

 ■of papers, in which one is at a loss whether to admire 

 ■most the untiring industry, the sagacity, or the wide 

 ■range of his work. Everything pointed to his taking a 

 foremost place in this branch of botany. 



But no one can be a mycologist without being drawn 

 into the study of plant diseases, in which fungi play so 

 Uarge a part. Vegetable pathology early attracted Cornu, 

 and he did much excellent work in it. We owe to him 

 the principle, now so familiar as to seem almost obvious, 

 ■of preventive treatment by the careful destruction by 

 burning of the di-bt is of plants which may harbour 

 iresting-spores. 



In 1868 a mysterious disease made its appearance 

 amongst the vines in the South of France. Planchon, 

 the professor of botany at Montpellier (who owed his 

 •early training to Kew), discovered the cause in an insect — 

 Phylloxera vastattix — introduced from the New World. 

 The injury which this ultimately inflicted on the principal 

 ■cultural industry of France lias been compared, and 

 probably with justice, to that of the most devastating of 

 ■wars. That France has risen triumphant above this, as 

 above so many other disasters, is but one example of the 

 indomitable courage of Us people. Cornu, from his official 

 position and special qualifications, was necessarily at 

 •once absorbed in the task — hopeless as it seemed at first 

 — of combating the scourge. For at least ten years, from 

 1872 onwards, he was occupied in little else. It is need- 

 less to enumerate the prominent position in various in- 

 •quiries which he filled ; the most important was that of 

 ■" secretaire de la commission academique du Phylloxera." 

 His memoir on the whole subject published by the 

 Academy has always seemed to me, for completeness and 

 finish, a model of what such a research ought to be. 



NO. 1652, VOL. 64] 



Cornu became the acknowledged authority on the sub- 

 ject of the Phylloxera. It had not been foreseen at first 

 that the scourge, when once emancipated from its 

 American home, might, and probably would, invade every 

 wine-growing country. There were those who thought it 

 impossible that it could cross the equator. The expecta- 

 tion was falsified and, in spite of all precautions, it made 

 its appearance at the Cape. I advised the Cape Govern- 

 ment to have recourse to Cornu, and his services were 

 as generously given as, I know, they were warmly 

 acknowledged. 



In I S84 Cornu succeeded Decaisne as Professor of Cul- 

 ture at the Musdum — a position, if not so extensive in 

 scope as that of the Director of Kew, scarcely less 

 onerous. I had made Cornu's acquaintance some years 

 before, and the circumstance of our similar official 

 positions speedily brought us into closer intimacy. The 

 position of an administrator under Government does not 

 suit every temperament. The enthusiast must expect 

 his ardour to be quenched with a good deal of official 

 cold water. To Cornu, who had something of the en- 

 gaging qualities of the iin'ridional, this was hard to bear. 

 My sympathy with him in his troubles, which were often 

 not small, was certainly sincere, but I am afraid often 

 seemed to him phlegmatic. In any case, the worries of 

 administration pressed hardly on him and, notwithstand- 

 ing the counsels of common friends, diverted him from 

 the scientific work which we all expected of him, and 

 which his really brilliant poweis entitled us to expect. 



.-\t the moment that Cornu entered on his new duties, 

 France had turned its attention anew to the field in 

 which, in the past, it had done so much — colonial enter- 

 prise. Cornu's ambition — and it was a legitimate one — 

 was to utilise the somewhat dormant resources of the 

 jardin des Plantes in the work, much on the lines of 

 Kew. For my part it was more than a pleasure to give 

 him all the assistance in my power. Agriculture is the 

 great civilising agency. To reduce nomadic and pre- 

 datory tribes to cultural pursuits is perhaps one of the 

 most eftective of missionary enterprises. Cornu threw 

 himself into the work with little short of passion. What 

 he accomplished, both for the French colonies and for 

 the enrichment of the gardens of his own country, with 

 resources more limited than we have at our disposal in 

 England, is to me surprising. But, unhappily, at the 

 moment when he had attained some measure of success 

 his forces failed him, and he was not allowed to see his 

 work fully crowned with accomplishment. 



Cornu was the most loyal of Frenchmen. Had he 

 been less so, he would not have sacrificed to the interests 

 of France the career he might have devoted to science. 

 I cannot but fear that while he lived the sacrifice he 

 made was not fully appreciated. Many of us have 

 wondered that a man who had done so much had never 

 been admitted to the Institute. But that recognition 

 could not have been long delayed, and this adds another 

 regret to his untimely death. 



W. T. Thisei.ton-Dyer. 



NOTES. 



M. Maupas, of Algiers, has been elected a correspondant 

 of the Section of Anatomy and Zoology of the Paris .\cademy of 

 Sciences, in succession to the late M. Marion. 



The Harben medal of the Royal Institute of Public Health 

 will be presented to Prof. Koch at a dinner to be held on July 

 24. Tickets may be obtained from the honorary secretary, 

 Dr. 'W. A. Bond. 



The ethnographical collection of shamanistic implements, 

 bead-work, musical instruments, &c. , presented by Miss Owen 

 to the Folklore Society, is on exhibition for a few days at the 

 rooms of the Anthropological Society, 3 Hanover Square, W. 



