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The factors determining the placental transfer of drugs used in labour were studied in the rabbit placenta perfused in situ with Krebs bicarbonate buffer. During concurrent maternal intravenous infusion of bupivacaine, lignocaine, pethidine and antipyrine, drug concentrations were measured in maternal arterial plasma and placental effluent perfusate, the flow rate and protein content of which were varied. Protein binding and content were also measured. Placental clearance of antipyrine, which is unbound, was unaltered by perfusate protein content, and increased with umbilical perfusate flow up to 2 ml/min. Clearance of lignocaine and pethidine, which were 20-30% protein bound, increased to a small extent with perfusate protein, and were flow-dependent up to the maximum perfusate flow of 4 ml/min. Clearances of bupivacaine, which was greater than 80% bound, increased markedly with perfusate protein but, though flow-dependent, was one-tenth to one-fifth that of the other drugs. Fetal binding and glycoprotein content were less than maternal, hence the equilibrium fetal: maternal ratio is predictably lower for the highly bound bupivacaine than for lignocaine or pethidine. Measured fetal: maternal ratios of bupivacaine were, however, only one-half to one-third of the predicted equilibrium values, suggesting that bupivacaine does not unbind readily in a single transit through the rabbit placenta. Thus, though bupivacaine crosses the placenta more slowly than the other drugs, the fetal dose of all these drugs will be greatest in healthy babies with good placental blood flows and high plasma proteins.

The study of fossil plants during the last quarter of a century has revealed a vast amount of information about the past history of many modern plant types. But while we have learned much about the Pteridophyta and Gymnosperms, singularly little information has been gained about the evolution of the plants now dominant in the vegetation of the world—the Angiosperms. In 1879 Darwin wrote the well-known lines to Hooker :—“ The rapid develop­ment, so far as we can judge, of all the higher plants within recent geological times is an abominable mystery. . . . I should like to see the whole problem solved'. Though 45 years have passed since this was written, we are still hopelessly in the dark about the origin and early evolution of this, one of the largest classes of living organisms. Interesting theories have been put forward as to the possible origin of the angiosperms, but these have been almost entirely unsupported by fossil evidence.

In the Karharbari Beds (Lower Gondwana) of Passerabhia (India), a very curious and characteristic fossil was found, to which the name of Ottokaria bengalensis was given by Zeiller. It is of interest, not only owing to its unusual form and problematical nature, but also on account of its association with Glossopteris indica and our uncertainty as to the reproductive structures of this form. Although leaves nearly allied to G. indica have been found in a large number of localities, not only in India but in Australia, South Africa, and Russia, fossils of the Ottokaria type are very rare, and, in addition to the Indian specimen, only one other example (from Brazil) has been described. The object of this note is to record the discovery in South Africa of a fossil which seems to be closely allied to, if not actually referable to, the genus Ottokaria . The specimen (illustrated in fig. 1) was sent by Mr. T. N. Leslie, F.G.S., to Prof. A. C. Seward in 1913, and was recently handed to me for investigation. It occurs as an impression in a rather coarse-grained sandstone, and was derived from the Vereeniging Sandstones of the Transvaal. The original description and figures of Ottokaria by Zeiller were published in 1902, and the specimen was recently refigured and described by Seward & Sahni in their revision of the Indian Gondwana plants, to which there is nothing further to add. The Brazilian specimen described by David White was called Ottokaria ovalis White, and was almost

Frederick Ernest Weiss was born on 2 November 1865 in Huddersfield, to parents of outstanding character and principles. His father, Charles John Philip Weiss, had been born in Germany, and was learning business in Holland when, in 1848, he was recalled to serve in the German army. At that time troops were being used to repress democratic risings in Germany, and since young Weiss held liberal and progressive views he refused to return. In consequence he was unable afterwards to go back to his home, and after spending ten years in Holland he came to England and established himself as a merchant in Huddersfield. He married Elizabeth Caroline, daughter of Frederick Pesel, a banker in Paris. One of her ancestors was the Hugenot, Thomas Delacourt, who came to England and settled at Wareham, where he was greatly esteemed for his piety and courage. After his death in 1733 he was commemorated in a tablet in the Congregational Church at Wareham as an intrepid supporter of civil and religious liberty in the troubled times at the end of the 17th century. Under James II his home was denounced as a conventicle, his goods were seized and were twice exposed for sale without the appearance of a single purchaser. Furthermore, at the risk of his life he removed from the Town Hall in the dead of night the heads of three gentlemen who had been condemned for their religious views by Judge Jeffries and executed. He hid these heads under his own bed and afterwards interred them. He took an active part in the revolution of 1688, joining William III when he landed at Torbay. Frederick Weiss was the third of five children. His father had attained a prominent position in the North of England as a merchant; he was a strong supporter of the Free Trade movement, and was a member of a delegation of British manufacturers and merchants which accompanied Richard Cobden on a visit to France to negotiate a commercial treaty. But when Frederick was only three years old his father died, leaving his mother to bring up and educate her young family on a slender income.

It is now generally recognised that the Benettitales occupied a dominant position in the vegetation during part of the Mesozoic period, and the elucidation of their reproductive structures is therefore of special importance. An additional stimulus has been given to the study of their remains by the suggestion, on the part of some botanists, that in the morphological features of these plants we may find a solution of the problem of the origin of the Angiosperms. The Estuarine beds of North East Yorkshire which had provided some of the earlier specimens had remained for a long time unexplored until the chance discovery of the beautiful Williamsonia spectabilis flower by Prof. Nathorst. Subsequently to Nathorst’s discovery I commenced a systematic examination of the Jurassic plant-beds of, Yorkshire, and Dr. Halle paid a visit to the coast in 1910 which resulted in the discovery of many important specimens. The previously described specimens belonging to the genus Williamsonia were found in the Lower Estuarine beds near Whitby, Runswick and Marske, while other well preserved examples were derived from the Middle Estuarine beds at Cloughton Wyke. The examples now to be described were obtained from the famous Gristhorpe plant-bed, which had not previously—so far as I know—yielded any examples of fertile structures clearly referable to the Bennettitales. The Gristhorpe bed is a layer of bluish-grey shaly clay, 1-3 feet thick, and containing very beautifully preserved plant remains. It is exposed on the shore at the northern end of Gristhorpe Bay, which lies between Scarborough and Filey; it runs up into the cliff (Bed Cliff) towards the north, but is here covered by Boulder Clay and unworkable. About four or five hundred yards farther it descends again and is found on the shore at the extreme southern (or south-eastern) end of Cayton Bay, but soon runs out to sea once more. It would appear that most of the fine specimens collected in former days by Williamson, Bean and other workers from this locality were obtained on the Gristhorpe Bay side, and this may perhaps account for the non-discovery of such recently discovered genera as Williamsoniella, Eretmophyllum and Caytonia We must also remember that coast-erosion is proceeding at a rapid rate in Yorkshire, and that the parts of the bed now exposed may well contain new plants, for in a distance of a few yards the assemblage of forms may change completely. It is unnecessary to describe the strata in which the plant-bed occurs, but it has been shown by Williamson that they belong to the Middle Estuarine Series of the Middle Jurassic.

Agnes Arber was born in 1879, the eldest child of a cultured family, whose members achieved distinction in different fields. Her father, Henry Robert Robertson, was an artist of Scottish extraction, whose father, a man of considerable botanical interests, also with gifts as an artist, had a private school at Slough. Her mother, Agnes Lucy Turner, was a descendant of Robert Chamberlain, who founded the china works of Chamberlain & Son at Worcester, and her mother’s relatives included John Davidson, the African explorer, and George Fownes, both of whom were Fellows of the Royal Society. Her brother, Donald Straun Robertson, M.A., F.B.A., was Regius Professor of Greek in the University of Cambridge and author of various books on classical subjects. Her sister, Janet Robertson, was a portrait painter. At an early age her mother inspired her with an interest in plants and her father gave her regular drawing lessons from the age of three until she went to school. This early training developed her powers of observation, and laid the foundation of the skill and artistry which later formed such a notable feature of her books and papers.

The continued expansion of air transport is bound up with its possibility of producing ever lower fares. Thus the future of both sides of industry depends on the success in this field. This paper notes some of the difficulties seen from the manufacturer's side in this rather inexact science. It is essentially a personal view not associated with any one Company's views, but based on some years of experience in the industry. It answers no questions, but is aimed rather at provoking discussions on some of the important issues, particularly those which tend to be taken for granted.It should be stated also at the outset that this paper is obviously affected by the current beleaguered state of the British airframe industry. There is nothing in it, however, which does not apply to any nation's airframe industry and it is not intended as criticism of the UK one. It is certainly not the intention to add to the volume of anti-British comment which is so valuable to our competition.

Professor Birbal Shni, the eminent Indian palaeobotanist, was born on 14 November 1891 at Bhera, a small town in the Western Punjab. He was the second son of Lala Ruchi Ram Sahni, who was later Professor of Chemistry at the Government College, Lahore. His grandfather owned a flourishing banking business at Dera Ismail Khan and practised chemical experiments as a hobby. Sahni’s early days were spent in a family and a neighbourhood which were unusually enlightened, and where education was held in high esteem. Plis father, who has been described as a profound scholar and a pioneer in social reform, was responsible for his early education. He encouraged the boy to collect plants, rocks and fossils, and during his vacations took him on excursions to the Himalayas and other places. Even before coming to England for the first time, he had travelled widely in Northern India and had journeyed as far as the borders of Tibet. After attending the Central Model School in Lahore, he proceeded to the Government College, where he had the advantage of learning botany from Professor S. R. Kashyap, and he obtained the degree of B.Sc. of the University of the Punjab in 1911. Immediately after taking his degree he travelled to England and entered Emmanuel College, Cambridge, where he worked until 1919. He obtained a First Class in Part I of the Natural Sciences Tripos in 1913 and was subsequently elected to a Foundation Scholarship in his college, and afterwards to a Research Studentship. He was placed in the Second Class in Part II of the same Tripos in 1915, a year in which Professor G. E. Briggs was the only botanist to obtain a First. About this time he took the Degree of B.Sc. of the University of London

The fossil flora of the Jurassic rocks of the Yorkshire coast has been investigated by many workers. At the beginning of last century a considerable number of the common plants were described by Brongniart and Phillips, and during the succeeding years excellent collections were made by such enthusiastic workers as Bean, Leckenby, and the two Williamsons. The close and critical study of these plants was, however, never accomplished until Prof. Seward9s critical work in the British Museum Catalogue appeared. This put the subject for the first time on a firm basis, and has very much simplified subsequent investigations. The earlier collectors confined their attention almost entirely to the accessible exposures of the Estuarine Series between Whitby and Filey, though some specimens are recorded from the neighbourhood of Runswick. In comparatively recent years, however, it has been found that the Lower Estuarine Beds in the Cleveland district were very fossiliferous, and large collections have been made by enthusiastic local geologists. As a result, several interesting forms were discovered in this district which were unknown farther south, and a systematic and critical examination of the whole flora was deemed advisable. The present work is the result of a re-examination of the specimens collected by the Rev. G. J. Lane, F.G.S., and Mr. T. W. Saunders, F.G.S., who have succeeded in obtaining a large number of fossils from the Marske and Upleatham quarries on Upleatham Hill. They kindly sent the most important specimens in their collections to me, for examination at Cambridge. I

Professor Seward, in his introductory remarks, referred to the publication in 1899 of Mr. Clement Reid’s “Origin of the British Flora,” and spoke of the more recent researches of Mrs. Reid which have considerably extended our knowledge of British Tertiary floras. He drew attention to the striking contrast between the early Tertiary floras and the present plant population of Britain, and to the changes exhibited by successive floras in geographical relationship and in composition. He emphasized the importance of reconstructing the geological background as well as the botanical features of the series of floras preceding and subsequent to the Glacial period. Reference was made to the more controversial question of the effect of the Ice Age upon the plant-world, and he expressed the hope that the discussion would enable botanists to form a more definite opinion on the crucial problem of survival or extinction of flowering plants when the British area was exposed to the maximum invasion of ice. Professor Seward offered a hearty welcome to Dr. du Reitz of Uppsala, whose work on Scandinavian floras provided particularly important data having a direct bearing upon the history of the Pre-Glacial and Post-Glacial floras of Britain.

The last few decades have seen enormous additions to our knowledge of the structure of fossil plants, and we have now a very complete acquaintance with the stems, roots, and fructifications of a considerable number of Coal Measure genera. But although this is the case, comparatively little is yet known about the structure of their foliarorgans. Renault's classic researches brought to light many interesting leaves, particularly from the Autum district; but scarcely any petrified leaves from the English deposits have been studied in detail. This no doubt, constitutes a very serious gap in our knowledge of the Palæozoie flora, and it is my intention to endeavour to make detailed studies of leaf structure in the principal groups of Coal Measure plants. The subject has important bearings in several directions, apart from a merely descriptive interest. It is now generally recognised that the leaves of plants growing in different habitats almost universally exhibit adaptations correlated with the physical conditions of their surroundings, and definite types of structure are developed according to the amount of water and light supplied. A considerable mass of evidence on this subject is being accumulated by the study of modern plants. It seems perfectly legitimate to use this evidence in the reverse manner, and from the characters of leaf structure to draw deductions as to the climate and conditions of growth in Coal Measure times. Leaves show these modifications more strikingly than any other parts of the plant, and hence a detailed know­ ledge of fossil leaves is of great importance in the discussion of the climatology of the Coal Measure period, and incidentally in regard to the question of the formation of coal.

This paper forms a further contribution towards the elucidation of the nature of the floras of Mesozoic times and of the affinities and systematic position of the plants composing them. When the author commenced work on this subject in 1910, a number of form genera of leaves had for many years been considered to represent the remains of ferns, though no fertile specimen had ever been found. It has since been shown that one of the most ubiquitous form genera, Taniopteris , included several species which were the fronds of bennettitalean seed plants (Thomas, 1915). Subsequently the form genus Sagenopteris was shown to be the leaf of a primitive angiospermous type, the Caytoniales, and not a fern frond (Thomas, 1925). We now come to deal with a group of plants whose leaves have been known for a long time under the names of Thinnfeldia and Lepidopteris . Here again we have evidence that these somewhat fern-like leaves belonged to seed-bearing plants

Albert Charles Seward was born at Lancaster in 1863. His father, Abram Seward, seems to have been one of those stalwart Victorians who owned an old family business and devoted his leisure to local administration, educational and religious work, serving as Mayor of the ancient town in 1877 and earning in his old age the title of the ‘grand old man of Lancaster’. Entering the Lancaster Royal Grammar School in 1874 the study of chemistry first attracted Seward’s interest, but his subsequent career was largely due to his hearing a course of University Extension lectures by J. E. Marr, an old boy of the school, who was just making his mark as a geologist at Cambridge. In 1883 he entered St John’s College, Cambridge. His contemporaries there included Sir Humphrey Rolleston, Dr A. B. Rendle, and Dr L. E. Shore, while one of his early friends was Dr Alfred Harker who had just taken his degree. A first class in the Natural Sciences Tripos, Part I, resulted in his election to a scholarship at his college, and this was followed by similar success in Part II when his subjects were geology and botany. Professor T. McKenny Hughes, who did so much for the study of geology at Cambridge, appears to have been responsible for directing Seward’s attention to the largely unexplored fields of palaeobotany. This led in 1886 to a year’s study of fossil plants in Manchester under Professor W. C. Williamson, the founder of modern palaeobotany in Britain.

Dr. G. C. Simpson, F. R. S.: It appears to me appropriate that a meteorologist should open this discussion, for the study of climates is a branch of meteorology. But while I speak as a meteorologist, I cannot speak for meteorologists, because on this subject there is no formulated meteorological opinion. What I say, therefore, must be taken as my personal opinion, with which other meteorologists may or may not agree. During the last few years I have given much thought to this problem of past climates and I have come to certain definite conclusions. I wish to lay these conclusions before you this afternoon, but in the short time available I can do little more than state them; I cannot hope to defend them by a reasoned exposition, but in most cases that has already been given elsewhere.

Among the fragments of plant remains, the structure of which is preserved, for us in the coal halls of the Lower Coal Measures of Lancashire and Yorkshire, Sigillarian stems have hitherto proved to be extremely infrequent. This fact has not escaped notice. Williamson, in 1872, remarked that “considering the abundance of Sigillariæ in the Coal-measures, it is marvellous that indisputable specimens displaying their internal organisation should he so rare; but such is the case.” Dr. Scott, in 1900, suggested that the rarity of such stems in the petrified state may be due to the infrequent occurrence of branching, “for, of course, it is in the case of small branches, rather than of great trunks, that petrifaction, such as to preserve the tissues, is most likely to have occurred. The recent reopening of a coal working at Shore-Littleborough, in Lancashire, rich in calcareous nodules containing plant petrifactions, a mine which is now, thanks to the liberality of Mr. W. H. Sutcliffe, F. G. S., being worked solely for the coal balls, has, however, resulted in the discovery of several well-preserved stems of ribbed Sigillarias of the Rhytidolepis type, which are described here. These specimens have been obtained by Mr. Lomax, one by one, as the result of a special search for this material, extending from July 1904 until the beginning of the present year (1907). Our thanks are due to him for the trouble he has taken to obtain the petrifactions, and for the skill with which he has prepared the sections.

Petrified stems belonging to the genus Sigillaria have hitherto proved to be extremely rare in the Upper Carboniferous rocks. The present paper contains the first full account of the structure of the Eusigillariæ or ribbed Sigillarias of the Rhytidolepis section. Hitherto our knowledge of the anatomy of such stems has been limited to the account of the bark given by Williamson, and to brief descriptions of specimens, including the vascular cylinder, by Professor Bertrand and Dr. Scott. The material, which forms the basis of the present study, consists of a patrifaction from the Lower Coal Measures of Shore-Littleborough in Lancashire, containing two well-preserved stems, lying side by side. The external surfaces of the ribs of both stems have been exposed by Mr. James Lomax, after much difficulty, and our thanks are due to him for his skill in preparing the sections. The characters of the ribs agree with those of the impressions known as Sigillaria scutellata , Brongn.

The rabbit placenta perfused in itu was used to investigate the factors determining the placental transfer of drugs used in labour. Each doe was given an intravenous infusion of pethidine, lignocaine, bupivacaine and antipyrine concurrently, and the umbilical circulation was artificially perfused with Mammalian Krebs' bicarbonate buffer. The umbilical flow rate was varied between 0.25 and 4.0 ml/min. Drugs were analysed in maternal plasma and umbilical effluent by gas liquid chromatography . Maternal protein binding and lipid solubilities were also determined, and were high for bupivacaine, low for antipyrine and intermediate for pethidine and lignocaine. The Cuv /Cma (mean +/- s.e.) at 1.0 ml/min for antipyrine was 0.74 +/- 0.036; for pethidine, 0.64 +/- 0.04; for lignocaine, 0.5 +/- 0.026; and for bupivacaine 0.072 +/- 0.006. This is the same rank order as is observed for the drugs in humans. The placental clearance increased with flow rates up to 2.0 ml/min for antipyrine and up to 4.0 ml/min and probably more for pethidine, lignocaine and bupivacaine. Transfer rate is therefore reduced by maternal protein binding, is flow-dependent at low flows, and permeability-dependent at high flows for the less lipid-soluble compounds.