Books of the Day
Fungi and Men
The Advance of the Fungi. By E. C. Large. (Jonathan Cape. 18s.)
AT first sight fungi do not seem to afford very promising material for a book intended for the general reader; indeed, their very
name suggests mustiness. But, in point of fact, there is no such thing as an uninteresting natural object, although our descrip- tions may contrive to make it appear so; everything in Nature
has the possibility of interesting, even fascinating, treatment. Mr.
Large has realised this, and has written a brilliant account of the subject made doubly interesting by emphasising at every turn the human relationships. He begins dramatically enough with a
quotation from the Gardeners' Chronicle of August 23rd, 1845 " A fatal malady has broken out amongst the potato crop. On
all sides we hear of the destruction. . . . There is hardly a sound sample in Covent Garden Market." Three weeks later came a more ominous announcement: " We stop the Press with very great regret to declare that the Potato Murrain has unequivocally declared itself in Ireland. The crops about Dublin are suddenly perishing . . . where will Ireland be, in the event of a universal potato rot? " Then follows a vivid account of the terrible Irish Famine, and of the utter inability of the experts to do anything really useful until, after bringing starvation and death to thousands of Irish peasants and untold misery to many thousands more, the disease slackened off. But that was only the beginning. Slowly but continuously science was advancing.
The disease was traced to a fungus, its rather complex life his- tory was worked out, and its relations with other fungi estab- lished. Finally, by the merest chance, a remedy was discovered.
A vine grower in Bordeaux, who suffered much from the depre- dations of passers-by, hit on the happy idea of spoiling the look of his grapes by spraying them with the slimy, greenish-blue precipitate formed when lime is added to a solution of copper sulphate. This not only stopped pilfering, but also protected against the destructive mildew. The relations between mildew and potato blight, though distant, were sufficient to justify trial of the Bordeaux mixture against the blight, and it proved entirely successful; the disease has since been little more than a nuisance, never a menace. Even that, however, does not end the story: it is always better to avoid a disease than to cure it, and search is now made for varieties resistant or, if possible, immune to the disease.
The suddenness and virulence of the potato blight led many to think that the fungus had arisen by spontaneous generation, but this was ruled out by Louis Pasteur. It was certainly not endemic in Ireland or in Europe, but only in America. How it came over will probably always remain a mystery. The first steamships have been rather widely blamed, but the author thinks the fungus more probably came over in some of the plant material which from the beginning of the nineteenth cen- tury was sent from one collector to another in some other country. This process of distribution is still going on, and the aeroplane has made matters worse, so that plant diseases and pests are now very widespread.
The rusts are dealt with at length. Red rust of wheat is an ancient pest, and the author describes the Roman ceremonial sacrifice of a red dog, the choice apparently being determined by the fact that the rust gave the fields a reddish appearance at about the end of April, when the dog star was supposed to be exerting a malign effect. It was early associated with the wild barberry, and the destruction of this plant was, in fact, the first preventive measure adopted : this was certainly being done around Rouen in 166o. Fortunately garden varieties are harm- less. The black stem rust, Puccinia srantinis, carne near to wrecking the Allied cause in 1916: it was estimated to have destroyed 30o million bushels of wheat in North America. Against this the strenuous cropping campaign of 1918 added only 25 million bushels to our home production. No cure is known, and one can only seek rust-resistant varieties of wheat. The difficulty is, however, that the causal organism has a number of biological strains differing in their power of attacking a par- ticular variety of the plant. A new variety of wheat may be resistant to one strain of fungul but badly attacked by another. Moreover, the number of biological strains is not limited : new ones can he formed by the union of two parent strains. Clearly there will always be plant-disease problems to worry farmers and gardeners.
It was long before effective collaboration could be arranged be- tween administrators and technical and scientific workers. In Great Britain we had -no general protection against plant dis- eases till 1907, when the Destructive Insects and Pests Act was passed. For this much credit is due to E. S. Salmon, of Wye, who persistently urged some check on the importation of dis- eased plants which up to then had been perfectly lawful. He interested Laurence Hardy, who used to raise the matter in the House of Commons. Punch had a characteristic picture of him asking for the nth time in a bored assembly when something would be done about American Gooseberry Mildew. Now, however, research workers, advisory officers and the Ministry of Agriculture's administrative staffs work closely together.
The difference from the old days is well seen in the study of the virus diseases of plants now causing great losses. A syste- matic plan of campaign has been thought out. Highly qualified workers in well-equipped laboratories carry out fundamental re- search to discover as much as possible about the virus and its relations with the plant: they are not concerned with finding remedies, but with gaining information. Other workers are studying the virus diseases of individual crops, especially potatoes, sugar beet, and tomatoes : they seek both information and remedies. The local advisors—the general practitioners of plant diseases—are given any information likely to help in advising farmers, and they pass on to the research workers any observa- tions likely to be of value.
Mr. Large tells his tale extremely well : who did the work, and how it was done, the mistakes, the gradual corrections, the accumulation of much apparently irrelevant detail, and finally the sudden fitting of all these scattered pieces into their proper places, making a coherent and illuminating picture out of a mass of jig-saw puzzle scraps. In the early days it was a long slow process; nowadays it is much more rapid. Now that Mr. Large has discovered this rich source of material, we hope he will explore it still further on its human side and tell about the men as they do the work. The story is full of interest, in spite of the old, but false, jibe that there is more personality in a third-rate actor than in the average Fellow of the Royal Society. The keen enthusiasm of the young man spending in some laboratory sunny days when the open country calls; the steady, continuous, self-sacrificing pursuit of some apparently trivial study that never can be explained to more that the select few; not infrequently, after years of patient and almost unrequited labour, just missing the goal, perhaps because some flaw at the outset has vitiated some of the result—all these things, which are constantly happening, could be made into a fascinating story. Browning expresses some of the tragedy in his Grammarian's Funeral, but Mr. Large might well think about fuller treatment. Meanwhile, the present book can be strongly commended both to scientific and to lay readers. E. J. RUSSELL.
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