A tetraploid blackberry bred by JIHI, which bears large crops of fruit of fine quality, is handed over to Messrs Laxton of Bedford, commercial fruit breeders, to be distributed as the ‘John Innes’ blackberry; it goes on general sale in 1934. This was the first of 49 new fruit varieties released by the Institute over the next five decades.

• JI fruit varieties reference list
• JI fruit varieties in the National Fruit Collection today. Search the National Fruit Collection Database for apple, cherry, pear and plum varieties using ‘Merton’ as your search term or choose a variety from the ‘JI fruit varieties reference list’

Ronald Aylmer Fisher, a statistician at Rothamsted Experimental Station, publishes The Genetical Theory of Natural Selection. The book represents a formal analysis of the mathematics of selection and creates a mathematical model of a population of hypothetical organisms. Using complex and innovative mathematical techniques, Fisher demonstrates both how favourable genes spread through a population and how unfavourable variations can survive, maintaining overall genetic diversity. This work places Fisher as one of three great founders of the field later known as population genetics, together with Sewall Wright and J B S Haldane. The book, though understood by few biologists at the time, fulfilled Wright’s prediction that it would ‘take rank as one of the major contributions to the theory of evolution’.

Nucleic acid was thought to be a tetranucleotide composed of one unit each of adenylic, guanylic, thymidylic and cytidylic acids. The ubiquitous presence of nucleic acid in the chromosome was generally explained in purely physiological terms.

During the 1930s the study of pollen incompatibility and sterility which has been going on for some years is extended from cherries, plums and apples to pears. Cytological examination of the varieties available begins. Morley Benjamin Crane’s pollination experiments (assisted by W J C Lawrence in the 1920s and A. G Brown from 1935) have allowed fruit trees to be grouped according to whether they are self-fertile (set fruit with their own pollen) or whether they require cross-pollination with another variety. By the end of the 1930s about a million pollinations have been made at JIHI to test the success of crosses that can happen in the orchard, and Crane is able to publish practical rules on which of the main varieties should be planted together to give good crops of fruit and which should not; his advice is regularly sought by fruit growers.

Despite their practical value, these findings in themselves offer no real insight into the genetic mechanisms determining incompatibility relations. The hypothesis that incompatibility relations are determined by a series of allelic genes, denoted by S1, S2, S3…, was formulated by E. M. East and A. J. Mangelsdorf in 1925, but it had not been possible to apply this insight to explain the more complicated cases of incompatibility relations in fruit. The first clue came from the young C. D. Darlington’s chromosome counts in a number of Prunus species in the mid-1920s which established that sweet cherries were diploid, sour cherries tetraploid and the plums hexaploid. These findings helped to explain some of the complexity in the relationships between pollen and style. Further advances are made by Dan Lewis (Assistant Pomologist) from 1940 using the more amenable species Oenothera organensis as a model plant. By inducing tetraploidy in this plant Lewis is able to analyse the relations of pairs of S alleles in detail. Lewis also develops techniques for studying pollen-tube growth in Oenothera which he is later able to apply to physiological studies of incompatibility in fruit.

See also:

The Fertility Rules in Fruit Planting. John Innes Leaflet No. 4., London: JIHI, 1940. On p. 2, Crane estimated that the total fruit crop of the country could be increased 10-20 per cent in value by correct inter-planting.

K Mather and W J C Lawrence, ‘Morley Benjamin Crane, 17 March 1890- 17 September 1983’, Biographical Memoirs of Fellows of the Royal Society, 31 (1985): 89-110.

Listen:

Listen to Dan Lewis speaking about his work on incompatibility relations, taken from an interview with BJ Harrison; 1991

In the 1930s Darlington’s investigations are concerned with pure cytology, with the elucidation of the movements, divisions and pairing of the chromosomes preceding and during the formation of germ-cells. His observations include comparing the behaviour of chromosomes in pure forms with that of the chromosomes in hybrids and various polyploids, where the processes are less regular. For these studies he uses plants with chromosomes that are of large size and in small numbers that can be easily observed. Darlington’s observations are then used to interpret the more difficult cases occurring in species that are the subjects of genetic study at JIHI. In particular Darlington’s studies are directed to determining the exact changes undergone by the paired chromosomes during the pro-phase of meiosis, the critical stage in regard to the mechanisms of both crossing-over and segregation. In general all Darlington’s observations confirm the chromosome theory of heredity. He concludes that the hereditary properties carried by the chromosomes not only determine the characters displayed by an organism but also the behaviour of the chromosomes themselves.

By 1931 Darlington has fifteen people studying under him, the largest cytological school of its kind in the world (Harman, 2004, p. 83). In the early years Darlington is assisted in his studies of meiosis by E. K. Janaki-Ammal (in diploid and tetraploid Tulipa), S. O. S. Dark (in the grasshopper Stenobothrus), Kenneth Mather (in triploid Tulipa), and Alice Gairdner (in Campanula persicifolia).

See also:

Harman, O. S., The man who invented the chromosome: a life of Cyril Darlington, Cambridge, Mass.: Harvard University Press, 2004.

Most of JIHI’s work in genetics, with Primula sinensis and other plants, continues to be concerned with linkage. However, in addition to supplying information on the association and position of genes in particular chromosomes, genetics work is now directed to providing material for testing C. D. Darlington’s theories of the inner mechanism of the nucleus determining meiosis and mitosis. Linkage studies of plants that have both tetraploid and diploid forms become particularly important. Cytological work is carried out in connection with every species that is the subject of genetic investigation at JIHI.

In 1929 Len La Cour publishes his first paper on ‘New fixatives for plant cytology’ in Nature. This is followed up in 1931 by ‘Improvements in everyday technique in plant cytology’ in the Journal of the Microscopical Society. These modestly titled contributions mark the start of La Cour’s career as a pioneer in the development of techniques for studying the chromosomes of plants (and animals). By this time he has become highly skilled in the preparation of chromosomes from a wide variety of difficult material from ferns to flowering plants and insects. At the age of 24 he is acknowledged as the expert in this field and he mentors all students who come to JIHI to see chromosomes. His experiments yield important improvements in pre-treatment, fixation, embedding and staining of material. Before his work methods, all using light microscopy, were only just satisfactory for ‘easy’ species with low numbers of large chromosomes. Even simple chromosome counts were fraught with problems, and each species and tissue required different treatments. La Cour’s techniques helped reveal the inner structure and coiling of the chromosomes, and Darlington’s contributions to cytological theory were based on his preparations.

See also:

Dan Lewis, ‘Leonard Francis La Cour 1907-1984’, Biographical Memoirs of Fellows of the Royal Society, 32 (1986): 357-375

Harriet B. Creighton and Barbara McClintock, at Cornell University, Ithaca, New York, demonstrate cytological proof of crossing-over in maize.  Their work shows that genetic recombination is caused by a physical exchange of chromosomal pieces. Darlington had laid the foundations of this idea in his work on meiosis in 1929-30. In contrast to ‘classical’ cytological theory, which favoured a system that retained the integrity of the chromosome, Darlington’s theory required breakage and rejoining of chromatids as the cause of crossing-over and the exchange of genetic information.

See:

C. D. Darlington, ‘A cytological demonstration of ‘genetic’ crossing-over (Hyacinthus)’, Proc. Royal Society of London, B, 107 (1930): 50-59.

Dan Lewis, ‘Cyril Dean Darlington 1903-1981’, Biographical Memoirs of Fellows of the Royal Sociey, 29 (1983): 113-157, esp. pp. 131-32.

The liberal policies of the University of London allow workers at affiliated research institutes to register for higher degrees without any formal or informal contact with a college or school of the University. This arrangement remains until 1960.

In the early days of the Institution, the social and educational welfare of the student gardeners was fostered by means of the Mutual Improvement Society, and the annual Cricket Match against the laboratory staff. The function of the latter fell into disuse as ‘age overtook the staff whereas youth was constantly renewed among the student gardeners’. The new Association inaugurated by E J Collins in 1931 aims to promote a closer union between the Mutual Improvement Association, and the Social and Cricket Clubs of JIHI. It also organizes an Annual Reunion Dinner for past and present student gardeners. In another move to strengthen ties with past members, the Association founds a journal, to ‘keep alive in them the object for which they were brought together — the improvement of Horticulture’. The first number of the Journal of the John Innes Gardeners’ Association appears in 1934 (Gardeners’ is dropped from the title in 1935 and the membership is broadened to include anyone who has worked for more than a year on the scientific or garden staff). The Journal appears annually until 1958 when the title changes to Journal of the John Innes Society, marking the Association’s merger with the John Innes Club to form a new staff society.

In October 1931 Kenneth Mather joins JIHI to begin a three-year Ministry of Agriculture scholarship to study genetics and cytology. He is put to work with C. D. Darlington, and within four months is writing his first paper on ‘The origin and behaviour of chiasmata’. In 1932, while Darlington is abroad, he collaborates with L H A Stone in the study of chromosome changes induced by X-rays. By carefully timing the irradiation with the visible changes in the chromosome during nuclear division he is able to show that the chromosomes reproduced into two strands recognizable by X-rays long before they were visibly double under the microscope. Mather gains a PhD in 1933 for two published works and two papers that were never published (on the cytology of Lilium and the genetics of Antirrhinum), in place of a thesis. In September 1933 he leaves JIHI to spend the third year of his scholarship under Herman Nilsson-Ehle at Svalöf in Sweden. On his return he gains a post with R A Fisher at the Galton Laboratory, University College, London but continues to collaborate with JIHI workers. He returns to JIHI as Head of the newly formed Genetics Department in 1938.

A reorganisation of the garden staff in the autumn results in W J C Lawrence taking charge of JIHI’s gardens. The demands that geneticists make on Lawrence’s garden staff are high: in the five years from 1931, 45-65,000 plants are raised annually to meet their requirements. Lawrence also becomes responsible for the education and discipline of the student gardeners. Under the old arrangements responsibility for the students was divided between the Garden Superintendent (William Lamberton) and Dr E J Collins (JIHI Botanist); the divided authority ‘had been taken advantage of by some young men and had led to trouble’.

Students receive a regular programme of lectures during their two-year course; in 1932 these are on soils and manures (Daniel Hall), Systematic Botany (E J Collins), Plant Physiology (F W Sansome), Plant Breeding (J Philp), Fruit (M B Crane) and General Horticulture (W J C Lawrence and J Newell). The lectures are supplemented by demonstrations, and students gain practical experience by working in rotation in the various ‘departments’ of the gardens. However, the scheme by which students spend three months of their training each year learning to grow ornamental plants ‘in good style’ is dropped and the ornamental plants are sold. This remains a very intensive course. JIHI’s prestige as a training establishment is reflected each year in the healthy competition for places.

The JIHI gardens continue to be used for the practical examination in Horticulture for the B.Sc. (Hort.) of the University of London.

Darlington’s book makes an impact that is ‘immediate and world wide’. At the fifth International Genetics Congress at Ithaca, New York (1932) the leading cytologists John Belling, Curt Stern, Harry Federley and C. L. Huskins devote substantial parts of their addresses to trying to disprove Darlington’s theories. Darlington ‘was given just five minutes to defend his views, and was shouted down by a storm of critics’ (Harman, 2004, p. 84). Across the cytological departments of the United States Darlington’s book is met with hostility. Darlington’s scheme of chromosome behaviour is imperfect; he has to make a priori predictions because technical difficulties mean that no preparations are available to him to test the facts directly. Leading critics, like Karl Sax at Harvard’s Arnold Arboretum, have many objections to Darlington’s generalisations and will not allow him the room to speculate without meeting their high standards of observational truth. His book is regarded as ‘poison for students’. Gradually the objections are retracted and by the end of the thirties Darlington’s scheme has become scientific orthodoxy (Harman, 2004, pp. 90-94, 102-4). His innovative book ultimately secures him a world reputation as a scientist ‘converting the chaos of the cell into the science of cytology’ (Lewis, 1982, p. 162), and his ideas become for a time the backbone of cytogenetics, with many more geneticists adding cytological methods to their work. Darlington’s contribution also means that the evolutionist can begin to use cytogenetic work. Darlington provides powerful arguments in the last chapter of his book, ‘The evolution of genetic systems’, for placing chromosomes at the centre of evolutionary enquiry.

See:

A. Sturtevant and G. Beadle, An introduction to genetics, Philadelphia: W. B. Saunders,1939.

D. Lewis, ‘Cyril Dean Darlington 1903-81’, Heredity, 48, 2 (1982): 161-7.

Harman, O. S., The man who invented the chromosome: a life of Cyril Darlington, Cambridge, Mass.: Harvard University Press, 2004.

Darlington is awarded a Rockefeller Fellowship which takes him away from JIHI from June 1932 to September 1933. During this time he is in company with some of the great names of genetics and cytology, spending 3 months at Woods Hole Marine Biological Laboratory (where he meets E. B. Wilson), 2 months in Berkeley, California (E. B. Babcock’s department), 6 months at California Institute of Technology in Pasadena (T. H. Morgan’s laboratory), where he collaborates with Theodosius Dobzhansky and meets George Beadle and Calvin Bridges, and 2 months in Kyoto. Darlington devotes his attention to showing that chiasmata (the X-like figures) corresponded with crossing-over in frequency in various organisms. Using material of maize and Drosophila available at Cal Tech, Darlington obtains results that confirm his simplified chiasmatype hypothesis.

On his return Darlington finds that his cytological school has been more or less dispersed and has to be rebuilt with the help of Margaret Upcott and Margaret Richardson. The cytological work progresses greatly, particularly in techniques at the hands of Len La Cour, Margaret Upcott, P. T. Thomas and Pio Koller. Darlington calls his group a ‘school’ because there are no departments at the Institution, only the Director and research workers.

On Darlington’s chiasmatype theory and how it differed from classical theory of the structure of chiasmata, see:

Dan Lewis, ‘Kenneth Mather 1911-1990’, Biographical Memoirs of the Fellows of the Royal Society, 38 (1992): 249-266, on p. 252.

J B S Haldane publishes The causes of evolution (1932), a collection of papers elaborating a mathematical theory of evolution, in which he demonstrates that Darwin’s theory of natural selection can be integrated with Mendel’s theory of inheritance to form a coherent account of evolutionary change. For this work Julian Huxley (in 1942) lionised Haldane (along with Ronald Fisher and Sewall Wright) as a founder of population genetics and a leading figure in the ‘modern synthesis’ or ‘synthetic theory of evolution’. Historians have considered the ‘modern synthesis’ either as a project to reconcile hitherto rival schools of biology (especially biometric and Mendelian approaches in Britain), or as a device to limit biological perspectives on evolution within the context of a struggle for institutional resources. Whichever narrative is accepted, it remains true that Haldane produced one of the first works of that enterprise, and that Britain, the home of the ‘Oxford School’ of broad Darwinian thinkers (Haldane’s first University), was very much involved in the effort to bring evolutionary theory into classical genetics (Harman, 2004, p. 112).

See also:

Julian Huxley, Evolution: the modern synthesis, London: George Allen & Unwin, 1942.

William Provine, The origins of theoretical population genetics, Chicago: Chicago University Press, 1986.

Ernst Mayr and William Provine (eds.), The evolutionary synthesis: perspectives on the unification of biology, Cambridge, Mass.: Harvard University Press, 1980.

Carla Keirns, ‘Evolutionary synthesis’, pp. 239-241 in A Reader’s Guide to the History of Science, ed. A. Hessenbruch (London: Fitzroy Dearborn, 2000).

Harman, O. S., The man who invented the chromosome: a life of Cyril Darlington, Cambridge, Mass.: Harvard University Press, 2004. See pp. 109-113.

Links:

 http://en.wikipedia.org/wiki/Modern_evolutionary_synthesis

http://students.washington.edu/gw0/modernsynthesis/

In December 1933 Rose Scott-Moncrieff joins the staff of JIHI to pursue her studies of the biochemistry of flower colour under the direction of J B S Haldane. She has already collaborated with JIHI staff for several years, and from 1931-32 held the title ‘volunteer worker’ at JIHI. Haldane encourages her to extend her early research on naturally occurring anthocyanins to the quite separate chemical and genetic studies of flower pigmentation that were being undertaken at the time. Armed with experience gained in Professor Robert Robinson’s labs in London and Oxford, Scott-Moncrieff is able to use new and quick qualitative methods; for the first time it has become possible to analyse whole plant families chemically as well as genetically. Scott-Moncrieff is able to show not only that chemical differences in pigment structure and cell environment are controlled by a single gene, but that these simple biochemical differences are similar and have the same or combined blueing effects upon flower colour throughout all of the families studied. The large range of species at Merton enable Scott-Moncrieff to make a wide survey of colour variations in plants, a survey that reveals surprising uniformity in the nature of gene action. Her work contributes significantly to the development of biochemical genetics: by the end of the thirties the basic biochemical nature of the action of genes involved in anthocyanin synthesis is clear.

From 1934 Scott-Moncrieff offers an annual short course on biochemical and genetical aspects of flower colour variation at the School of Biochemistry in Cambridge for Part II Biochemistry and Botany students. Her work also reaches a wider public through her BBC broadcast on ‘The Colour of Flowers’ in 1936.

See also:

Rose Scott-Moncrieff, ‘The classical period in chemical genetics: recollections of Muriel Wheldale Onslow, Robert and Gertrude Robinson and J B S Haldane’, Notes and Records of the Royal Society of London, 36, 1 (1981): 125-154.

As Professor of Genetics at University College (a part-time post), Haldane begins lectures on plant genetics to elementary and advanced students in London. These lectures are made possible by the generous provision of living and dried plant material, and lantern slides, by the John Innes Horticultural Institution.

Morgan receives a Nobel Prize in Physiology or Medicine for his development of the theory of the gene. He is the first geneticist to receive this award.

http://nobelprize.org/nobel_prizes/medicine/laureates/1933/morgan-bio.html

http://nobelprize.org/nobel_prizes/medicine/articles/lewis/index.html

Investigations into the inheritance of immunity to woolly aphid in apples carried out by Morley Benjamin Crane at JIHI in collaboration with East Malling Research Station continue. Considerable progress has been made in the selection of immune seedlings and the assessment of their value as rootstocks. Representatives of some of the immune clones are sent to Argentine, Australia, Canada, India, Morocco, New Zealand, South Africa and Russia, where they undergo entomological tests to determine whether their resistance to attack will be maintained in different environments.

Only 22 per cent of the Primula sinensis seeds sown in 1933 survive to give living plants. This loss is a catastrophe for the geneticists and results in W J C Lawrence beginning to look for an alternative growing medium. He is helped at the start of his search by Messrs Suttons of Reading whose resident expert on primulas had already devised a successful special compost. Lawrence adapts the recipe, changing three variables at once, and in mid-winter 1934 1,000 plants die or wilt as before. J B S Haldane said he should be sacked for his foolishness!

To prevent another disaster in the 1935 crop, Lawrence begins to investigate the whole procedure of making seed and potting composts. Assisted by John Newell, he makes a large number of tests on the ingredients used for potting composts, including pH determinations, seed germinating capacity, and the effect of steam sterilisation on germination and growth. His aim is to produce a standard sterilised compost giving superior results. By 1935 Lawrence has established the optimum amounts of N, P and K fertilisers and introduced two standard soils for use at JIHI, one for sowing and one for potting, while continuing his investigations. His work pays off: the 1935-36 crop of primulas is one of the best crops the JIHI has ever had and ‘primula wilt’ is eradicated.

Lawrence begins to consider whether the composts will work for all species and continues testing. After hundreds of trials, Lawrence arrives at two basic composts, a base fertiliser for use in the potting compost and a standard feed. The formulae of these, as yet unnamed composts, are published in 1938. The name ‘John Innes Compost’ is allotted in 1938-39; the horticultural retail trade in the composts makes ‘John Innes’ a household name.

Before John Innes composts were developed, gardeners and horticulturalists made up their own mixtures. These were subject to so many unstandardised conditions that it was impossible to identify the cause of failures to grow healthy, vigorous plants, and sterilised soil was hardly ever used for potting, either in private or commercial practice. It was common to raise three times as many seeds as the number of plants required to allow for deaths from damping off and other troubles.

See also:

W. J. C. Lawrence, Catch the tide: adventures in horticultural research, London: Grower Books, 1980.

Hit by wider economic recession, the John Innes Trustees are forced to reduce the annual income of the Institution from £21,000 to £18,000 in 1931. In 1935 the loss is partly offset by a Ministry of Agriculture (Development Fund) grant of £885, rising to £1000 per annum in 1940. Daniel Hall obtained the grant to appoint an Assistant Pomologist (Dan Lewis) and another assistant (P. T. Thomas) to help Morley Benjamin Crane with the genetics and cytology of fruit breeding. In 1940 the income of the Institution falls again to £11,000. The Development Commissioners step in with a block grant of £3,000. The supplementary grant is made to reflect ‘the special circumstances in which the Institution finds itself as a result of the war’ and there are no guarantees that it will be renewed annually. From 1st April 1940 the administration of the grant is taken over from the Ministry of Agriculture by the Agricultural Research Council (founded 1931).

Outside of his work for the John Innes Horticultural Institution, Haldane works on various problems of mutation and selection based on the mathematical tools that he had developed. In an outstanding paper in 1935 Haldane provided the first estimate of the rate of mutation of a human gene based on his calculation of the equilibrium between mutation and selection. Here he established what came to be called the indirect method of estimating mutation rates.

In July C. D. Darlington publishes three extensive papers on the internal mechanics of the chromosomes in species of Fritillaria as determining their movements in the phases of meiosis. This difficult question has become the subject of active controversy; debate is conducted with some animus at the International Botanical Congress in Amsterdam following Darlington’s paper on crossing-over and chromosome disjunction. His former colleague, C L Huskins, is at the centre of arguments against him in all the sessions. Privately, Huskins offers to come across the Atlantic and punch his head off (Harman 2004, p. 88). Cytologists have not seen these processes for themselves, and in their discipline ‘seeing’ is believing; they are intensely sceptical about Darlington’s observations. Darlington’s scheme is complex and many of the details are speculative.

Harman, O. S., The man who invented the chromosome: a life of Cyril Darlington, Cambridge, Mass.: Harvard University Press, 2004, pp. 109-115.

Antagonism has developed between the Director A D Hall and some of the old Batesonian staff, and between J B S Haldane and Hall. While the senior member of the old Batesonians, Caroline Pellew, is away in South Africa, the affairs of the Institution come to a head. Supported by their colleagues, C. D. Darlington and Dorothy Cayley present proposals to the Governing Council for a new deal. Their demands include that Staff should have written contracts and a fixed age of retirement as in Universities. In breach of normal procedure, the proposals are put direct to the Council, not through the Director.

The reorganisation that follows results in the establishment in 1937 of four new departments: Genetics, Cytology, Pomology and Biochemistry, each with a head and one permanent assistant. Darlington is made head of the Cytology Department. Hall is asked to stay on as Director following an interview between Haldane and the Council at which Haldane fails to impress with his plans for the Institution.

Haldane leaves to fight in Spain in December 1936; his parting shot is a letter to Dame Helen Gwynne-Vaughan, head of the Botany Department at Birkbeck College in London, giving his opinion that while Hall is Director the JIHI should not be recognized by the University of London as a place for training PhD students in genetics. Haldane, who had originally been appointed on the understanding that he would succeed Hall, formally resigns on 1 October 1937 and takes the Weldon Chair of Biometry at University College, London. During his time at JIHI Haldane has improved standards of accuracy in experimental work, introduced new mathematical approaches to the handling of biological data, and facilitated the development of biochemical approaches to genetics.

Listen:

Listen to C D Darlington describing the circumstances of the crisis, taken from an interview with BJ Harrison; 1979

A milestone of evolutionary genetics, Dobzhansky’s book is sometimes considered as the first account to embody the spirit and direction of the ‘modern evolutionary synthesis’. However, this is to ignore the important early contributions of E. B. Ford’s Mendelism and Evolution (1931) and J B S Haldane’s, The Causes of Evolution (1932) in Britain. C. D. Darlington’s Recent advances in cytology (1932) initiated a further new strand of evolutionary genetics. He wrote about the importance of recombination as a source of genetic variation available for natural selection and led the field in understanding its evolutionary importance. Darlington’s approach and his introduction of the concept of genetic systems is not employed in a wider sense until Dobzhansky’s book; Dobzhansky cites him more than any other researcher besides Alfred Sturtevant and Sewall Wright. Through the medium of this book Darlington’s ideas come to be incorporated into the mainstream of genetics. Harman explains Darlington’s failure to gain the credit he deserved to his ‘anomalous position [as] a cytologist extrapolating to evolutionary phenomena’ (Harman 2004, p. 113).

For a summary of the many histories of the ‘modern evolutionary synthesis’ and Darlington’s place in evolutionary genetics see:

Harman, O. S., The man who invented the chromosome: a life of Cyril Darlington, Cambridge, Mass.: Harvard University Press, 2004, pp. 109-115.

War with Germany now seems inevitable. Strategies for food and agriculture developed between 1936 and 1938 have formed an important part of Britain’s re-armament programme. By 1938 plans for Britain’s self-sufficiency in food are well advanced.

The Seventh International Genetical Congress takes place from 23rd-30th August 1939 in Edinburgh. The Congress, usually held every five years, is two years late, the Russians having abandoned their plan to hold the Congress in Moscow in 1937. The suppression of genetics in Russia has begun and the Russians withdraw ten days before the Congress. Nikolai Vavilov was to have been the President but his place has to be filled by Francis Crew.

On Wednesday 23rd August 600 geneticists from 55 countries assemble in Edinburgh. By the end of Thursday 24th August international events begin to take over, the German delegation are the first to leave, followed by the Dutch, Hungarian, Scandinavian and Swiss. The Congress closes prematurely on the 29th of August.

At the Congress leading British and American geneticists consider a question set them by the Washington-based Science Service, an organization for communicating science to the public: ‘How could the world’s population be improved most effectively genetically?’ Their response is published in Nature on 16 September 1939. This short statement, later dubbed ‘The Geneticists’ Manifesto’ is often heralded as the moment when geneticists, several of them active in the eugenics movement, spoke out to challenge the scientific and political assumptions of eugenics. J B S Haldane and C. D. Darlington are among the signatories

On September 1st German troops invade Poland. Adolf Hitler does not respond to Chamberlain’s ultimatum that German troops be withdrawn from Poland immediately. On September 3rd Prime Minister Neville Chamberlain announces on the radio that Britain is at war with Germany.

See:

http://www.eyewitnesstohistory.com/vocham.htm

On Britain’s war preparations in 1939, see:

http://www.bbc.co.uk/ww2peopleswar/timeline/

Daniel Hall retires on 30 September 1939. During his thirteen years as Director the teaching and research activities of JIHI have extended. The number of exhibitions offered to student gardeners increased from eight to twelve and the total staff from 52 to 65. Hall’s legacy includes affiliation with the University of London, and the biennial summer courses in genetics and cytology which bring the Institution into regular contact with teaching and research students.

C. D. Darlington once unkindly described Hall as in the stage of ‘advanced comitteeosis’ when he joined JIHI. However, Hall’s personal connections with the powerful organisations behind agricultural and horticultural research proved extremely valuable to the Institution, both in terms of grants and additional land resources for the extension of fruit trials.

Hall’s stature within Britain’s agricultural research community can be gauged by the book Agriculture in the twentieth century: essays on research, practice and organization (1939), a series of essays written in celebration of his seventy-fifth birthday by some of his old students and colleagues showing the progress in agricultural science and practice since he had begun his career.

Darlington’s first job as the new Director is to prepare the Institution for war. The war affects JIHI in three ways: air-raid precautions, enlistment, and food production. Darlington arranges for four air-raid shelters to be built, and for all irreplaceable books and journals to be sent to Long Sutton and Wisley for storage. JIHI’s library is used for monthly Air Raid Protection (A.R.P.) lectures and many members of staff (including Darlington) assist in A.R.P. services. Nearly all the student gardeners and several members of the permanent garden staff have become liable for military service. The depletion of staff is partly made good by the employment of boys. The garden work is reduced to manageable proportions by transferring about half the land from experimental to economic crops. To compensate for the reduction of area under experimental crops and reduce the cost of experiments, genetics work is partly transferred indoors. Kenneth Mather uses Drosophila for experiments, with a view to applying the principles to crop plants.

The emphasis of research is re-directed towards the immediate problems of food production in war. Darlington encourages staff to turn to problems of seed production at home so that growers need not rely on imported supplies. M B Crane and Mather work on raising hybrid tomato seed, G H Beale works on beans, Dan Lewis on cucumbers and Crane on marrows. The formulae of the useful seed and potting composts that have been devised by William Lawrence and John Newell for growing difficult experimental plants are more widely publicised, and beginning in February 1939 leaflets on composts, soil sterilization, seed production and fertility rules for fruit-planting are produced and distributed. For some time ‘John Innes’ composts and base fertilizer have been available to the public. The standard ‘feed’ devised at JIHI for use with pot-plants is now being sold by fertilizer manufacturers in two forms: John Innes Feed ‘L’ for liquid feeding and ‘D’ for dry feeding.

Listen:

Listen to C D Darlington speaking about leaflets distributed by the JIHI during the war, taken from an interview with BJ Harrison; 1979