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It will be noticed that the scheme I have outlined is closely analogous to the system already general in connection with medical training, where the lecturing and professorial staff on the technical side consists almost entirely of old students (occasionally from other colleges) who are beginning to make their way professionally, or who, by the time they have become professors, have actually made their way to the highest ranks of their profession.
HARVEY AND THE PROGRESS OF MEDICAL SCIENCE.1
FTER some introductory remarks, Dr. Roberts ferred to Harvey's work, and especially to his great discovery of what is commonly spoken of as the circulation of the blood," though his published treatise is really on the movements of the heart and of the blood." He re-affirmed their implicit belief in the absolute priority of Harvey's claim to this discovery, and spoke of its magnitude and far-reaching effects, which had been described in various and glowing terms, in no way aggerated. Nor must they forget the formidable difficulties under which Harvey carried out his investigations; the profound errors which he had to combat and overthrow, and the confusion he had to clear away; his indomitable perseverance; and the masterly yet courteous manner in which he disputed and ultimately overcame the objections which had been raised against his views.
The orator then gave an outline of Harvey's career, dealing more especially with his association with the College of Physicians, where he held the position of Lumleian Lecturer from 1615 to 1656, in the very first course of lectures presenting a detailed exposition of his views concerning the circulation of the blood, which continued to form one of his subjects for several years. the deed by which Harvey conveyed to the college his estate, he laid down three definite and distinct injunctions or instructions as to the subject-matter of the oration, which it was their duty to follow. The first injunction
is that "there shall be a commemoration of all the benefactors of the said College by name and what in particular they have done for the benefit of the said College, with an exhortation to others to imitate these benefactors and to contribute their endeavours for the advancement of the society according to the example of those benefactors."
Dealing with this injunction, Dr. Roberts first mentioned individually Harvey himself; Thomas Linacre, the practical founder of the College of Physicians; and John Caius. He then considered generally as benefactors those who had held high office, alluding specially to that of President; those who had founded lectureships, or had given endowments for prizes, medals, or scholarships; those who had contributed to the library or to the general funds; and those who by their professional or scientific attainments and achievements, as well as by their high personal character, general culture and scholarship, and intellectual and moral qualities have shed unfading renown and lustre upon the College of Physicians.
In discussing the second injunction, namely, to "exhort the Fellows and Members of this College to search and study out the secrets of nature by way of experiment," the orator made a passing allusion in favour of vivisection, claiming for this method of investigation the cordial support of the medical faculty as a whole, with comparatively few exceptions. After referring to what the College had done as a body in advancing scientific research, he enlarged upon the great activity and promising aspects of modern research, more particularly in relation to subjects connected with the medical profession, and expressed his belief that Harvey would be amazed and fully satisfied were he to come on the scene at the present time, and realise the extent and theroughness with which his exhortation is being carried into effect in all directions. Dr. Roberts then gave an abstract of what he had prepared for the oration with reference to the progress of know
1 Abstract of the Harveian Oration delivered at the Royal College of Physicians on June 21 by Dr. Frederick T. Roberts.
ledge and practice in connection with the circulatory system since Harvey's time, and the methods by which it had been brought about. He also directed attention to some of the
more prominent examples of the beneficial results on an extensive scale of scientific and practical research, and alluded specially, as being closely connected with the circulatory system, to the brilliant victories which had been achieved against malaria in various parts of the world, many of them forming an integral part of this vast Empire. While paying a tribute of respect and admiration to all those who at the risk of life and health have gone forth to dangerous climates to study and fight against this and other tropical diseases, Dr. Roberts mentioned specially Dr. J. E. Dutton, the latest martyr of science, as he had been aptly called, whose lamented death recently occurred on the Congo, where he had gone to study sleeping sickness on behalf of the Liverpool School of Tropical Medicine. He expressed on behalf of the college their deep sense of the great services which Dr. Dutton had rendered to the medical profession and to humanity, their profound regret at the premature cutting off of such a valuable life and promising career, and their heartfelt sympathy with his bereaved family and friends.
The orator concluded as follows:--The last and most agreeable duty laid upon me by Harvey's direction is to exhort the Fellows and Members, for the honour of the profession, to continue in mutual love and affection among themselves, without which neither the dignity of the College can be maintained, nor yet particular men receive that benefit by their admission into the College which they might expect, ever remembering that concordia res parvae crescunt, discordia magnae dilabuntur." With regard to the future position and reputation of this college in relation to scientific research and the progress of medicine, there can be no doubt or misgiving when we see amongst our younger fellows and members so many who are endowed with great abilities, who are full of energy, intellectual vigour, and enthusiasm in their work, and whose achieve ments have already brought them into conspicuous prominence and, in some cases, into the foremost ranks of our profession. May we not confidently hope that they will also ever keep in mind Harvey's last exhortation, and unflinchingly strive to maintain the high standard of character and conduct which he has placed before them? But should they at any time feel the need of an example, a stimulus, or an inspiration, let them steadily fix their attention and thoughts upon the personality, the life, and the work of our immortal and beloved Harvey," whom it is our privilege and pride and happiness to commemorate on this anniversarv.
HIGH TEMPERATURE RESEARCH ON THE
A N elaborate investigation of the melting points of the felspars, devised and carried out by Messrs. Day and Allen in the physical laboratory of the United States Geological Survey, is described in a memoir just received.' The geological importance of laboratory research at high temperatures was strongly urged by the late Clarence King and Dr. Becker, and the well known work of Dr. Carl Barus has already furnished petrologists with a number of valuable data. The laboratory, discontinued in 1892 for want of funds, has been re-established by the exertions of Dr. Becker, and the piece of work before us has been in part subsidised by the trustees of the Carnegie
The authors describe in detail, for the benefit of other experimenters, the thermoelectric method by which they have been enabled to measure high temperatures with an error of not more than one degree. It was also found necessary to adopt some method of determining the instant of melting (where such exists) independently of the personal judgment of the operator. It appears that in
1 "The Isomorphism and Thermal Properties of the Felspars." Part i. Thermal Study By Arthur L.. Day and E. T. Allen. Part ii. Optical Study. By J. P. Iddings. With an introduction by George F. Becker Pp. 95; xxvi plates. (Washington, 1905.)
We reproduce in tabular form the chief numerical results obtained. The general conclusions arrived at are of great importance. The melting point curve for the lime-soda-felspars, as well as the curve of specific volume, is continuous, and not very different from a straight line, and we have almost conclusive proof that this group of minerals forms a truly isomorphous series. Further, it belongs to type i. of Bakhuis Roozeboom, the melting point falling steadily from one end of the series to the other. Here a further point of interest arises. According to theory, the crystals first formed from the fused mass should be richer in anorthite than the liquid from which they separate, and should contain an increasing proportion of albite as crystallisation proceeds. Day and Allen, however, verified in several cases that their crystals had the same composition as the mother liquid. This can only be due to undercooling, the beginning of crystallisation being deferred until the temperature had fallen below the range proper to normal crystallisation. Those natural rocks in which the felspar crystals show a zoned structure (the outer zones richer in albite) must have crystallised without undercooling, and, indeed, their felspars
of different experimenters is largely attributable to this fact. The method followed was therefore to plot as a curve the relation between temperature and time, and to note the place where a change in the shape of the curve indicates an absorption of latent heat. To avoid the disturbing influence of impurities, the several felspars to be examined were prepared artificially. Thin slices of the crystallised products were studied optically by Prof. Iddings, and they are illustrated in the memoir by a series of beautiful plates.
Anorthite was the felspar most easily crystallised, and its curve gave a sufficiently sharp melting point at 1532°. Other varieties
amined had the compositions Ab, An,, Ab, An,, Ab, An,, Ab,An,, Ab,An,. These gave progressively lower melting points; but it was found that, in passing from anorthite towards the albite end of the series, viscosity rapidly increases and obscures the phenomenon of fusion, the break in the curve of heating becoming for Ab, An, a barely perceptible deviation. For albite, and also for orthoclase, the method fails to give any result, and in a certain sense it may be said that the alkali-felspars have no melting point. In this connection, a special series of experiments gave some remarkable results. A small fragment of crystalline albite, embedded in albite glass, was heated to 1200° and slowly cooled. Thin slices showed that the crystal had melted to a glass only along cleavage and other cracks. The experiment was repeated with higher temperatures of heating up to 1250°, and it was found that, though the lanes of glass encroached more and more upon the crystal, considerable relics of the latter were still left, preserving undisturbed their original orientation. It thus appears that mineral like albite, melts to an ultra-viscous liquid, may be maintained for half an hour at a temperature well above its normal melting point without being completely fused. It seems doubtful whether the crystalline substance at such a
PRIMITIVE RELIGIOUS ART.1
WE have on several occasions directed attention
works by American ethnologists dealing with investigations on the meanings of the designs and patterns of aboriginal decorative art. This fruitful and interesting field of inquiry is by no means exhausted, and two papers on the subject have recently been published by the American Museum of Natural History which merit the careful attention of students. Dr. Clark Wissler has made a valuable study of the decorative art of the Sioux Indians which is a model of clear and concise expression and of adequate illustration. As he truly states, the investigation becomes psychological, because it is necessary to know what ideas the artists have of their designs, and what motives lead to their execution. The assumption that all primitive decorative designs are executed with consciousness that they symbolise some definite object or relation in nature is fairly supported by the facts so far accessible, but does it follow that these symbolic designs were produced by a gradual transition from the realistic representation? That some of them were so produced has been satisfactorily demonstrated; but is this the law of growth for decorative art? It appears, among the American Indians, that the more abstract the idea, the simpler and more geometric the design. On the other hand, it is obvious that a vigorous conventionalisation of representative forms must tend to reduce them all to a few simple geometric designs. In such an event, confusion as to the symbolic aspect of similar designs must arise in the minds of the artists, necessitating re-interpretation or creation of new symbols. Thus any given interpretation need have no certain relation to the origin of the design itself; indeed, the association of the symbol and the idea can be shown in some cases to be quite secondary. Amongst the Sioux there are two main kinds of decorative art-realistic painting and conventional bead- or quill-work; the former is done by the men and the latter by the women, and there is every reason for assuming that the pictographic mode is on the whole the older. One sex has often appropriated the designs used by the other to express divergent ideas, and thus we see how even within the same tribe two or more modes of expressing symbolic motives may make simultaneous use of the same graphic designs.
In a short paper of fifty pages on the decorative art of the Huichol Indians of Mexico, Dr. C. Lumholtz has managed to crowd some 350 figures, so that we have abundant material for study. All these designs, he says, are expressions of religious ideas that pervade the entire existence of these people; in other words, they are permanent prayers. Girdles and ribbons, inasmuch they are considered as rain serpents, are in themselves prayers for rain and for the results of rain, namely, good crops, health, and life. All the designs on pouches, shirts, skirts, and so forth express prayers for some material benefit, or for protection against evil, or adoration of some deity. Thus the magic double water-gourd, even in its most conventionalised form, means a prayer for water, the source of all life and health. Animals like the puma, jaguar, eagle, &c., express prayers for protection, as well as adoration for the deity to which the creatures belong. The little white flower, toto, which grows in the wet, corn-producing season, is at once a symbol and a prayer for corn, and in all sorts of forms it is to be found woven in their costumes. Flowers play, and always have played, an important part in the religion of these Indians; with them flowers, like the plumes of birds, are prayers for rain and life. Dr. Lumholtz doubts if there is such a thing as ornamentation solely for decorative purposes among the Huichol, or, for that matter, among any primitive people. Prof. Boas points out that on the whole the style of decoration of ceremonial objects differs considerably from that of the ornamental parts of garments. The former are crude and pictographic, with slight tendency to ventionalism, while the latter are regular, well executed, and strongly conventionalised, and the general character 1 "Decorative Art of the Sioux Indians." By Clark Wissler. Bull. Am. Mus. Nat. Hist., vol. xviii., pp. 231-278. (New York, 1904.)
"Decorative Art of the Huichol Indians." By Carl Lumholtz. Mem. Am. Mus. Nat. Hist. Whole series, vol. iii. Anthropology, vol. ii. part iii. (New York, 1904.)
of these designs much resembles that of similar designs found in other parts of Mexico and in Central and South America. These textile designs, which are of great variety and beauty, acquire much more interest from the suggestive interpretation of their symbolism which Dr. Lumholtz has afforded us.
The American Museum of Natural History is to be congratulated on possessing collections about which so much valuable information has been obtained, and students are to be congratulated on having these riches made accessible to them by means of such beautifully illustrated memoirs. A. C. H.
AT the recent congregation of the University of Leeds a fellowship of the value of 100l. was awarded to Mr. Joseph Marshall, of the Victoria University School of Chemistry.
PROF. STEPHEN M. DIXON, holder of the chair of civil engineering in the Dalhousie University, Nova Scotia, has been appointed to the new professorship of civil engineering in the University of Birmingham.
It was mentioned by the principal of King's College, London, at the recent distribution of prizes and certificates to the successful students that Prof. W. G. Adams, F.R.S., is about to resign his chair after forty-two years' work in the college.
THE Rogers prize of 100l. of the University of London has this year been awarded to Dr. B. J. Collingwood for his essay on Anæsthetics, their Physiological and
Clinical Action." The essay submitted by Dr. A. G. Levy was highly commended, and an honorarium of 50l. was awarded him.
A MOVEMENT is now in progress for providing the North Wales University College with new buildings at an estimated cost of 175,000l., of which 30,000l. has been already promised. The site has been given by the corporation, which has presented the deed of gift to Lord Kenyon, president of the college. The president has expressed the hope that the rest of Wales will follow the liberality shown at Bangor, and that there will be no more need for the best professors of the college to leave Bangor for more lucrative positions in other parts of the United Kingdom.
ACCORDING to the Electrician, a committee of the Liverpool City Council, instructed by the Finance Committee to report as to how far the educational methods employed at the Liverpool University were in the interests of the city and met its requirements, have reported that they are satisfied that the University is doing its best to ensure that its students shall enter into the business of life with their intellectual powers fully developed by providing the students with a wide range of duty and sound methods of instruction, and they have therefore recommended that the sum of 10,000l. should be granted during the present year upon the same conditions under which a similar grant was made for the first time last year. The report
of the finance committee has come before the City Council and has been approved. Of the amount in question, 1000l. is devoted to scholarships for Liverpool men.
COPIES have been received of the Johns Hopkins University Circular containing the programme of courses for the session 1905-06, and of the Yearbook of the Armour Institute of Technology, Chicago, for 1905-06. The Johns Hopkins University will begin its thirtieth year of instruction next October. The work will be carried on
in three divisions:-The graduate department, in which arrangements are made for the instruction of advanced students in the higher branches of science and literature; the medical department, in which students (men and women) who have already received a liberal education are received as candidates for the degree of M.D., and in which doctors of medicine may attend special courses; the collegiate department, in which students receive a liberal education leading to a degree. The Armour Institute of Technology was founded in 1892, and the work of instruction was begun in September, 1893. Courses are now offered in mechanical engineering, electrical engineering, civil engineering, chemical engineering, fire protection engineering, general science, and architecture, and all lead to the degree of Bachelor of Science.
In the course of an address on degree day, July 8, at the University of Liverpool, Lord Derby, the chancellor, said that since they last met they had several laboratories, some complete and some in progress. Another building, to be opened in November, will be for the study of natural history. They had also an extension to record of the chemical laboratories, to provide accommodation for the department of physical chemistry, and an addition to the existing department. This had been provided at an estimated cost of 10,500l., which the president of the council, Mr. E. K. Muspratt, had promised to contribute. Since they last met 10,000l. had been given by Mrs. Barrow, the borough of Birkenhead had given an annual grant of gool., and a grant of 10,000l. had been received from the Liverpool City Council, 1000l. from the county of Lancaster, from Cheshire 300l., and from the borough of Bootle 5ool. The sum of 1500l. had been given to endow a lectureship in memory of Sir William Mitchell Banks. Mr. E. Whitley had promised 1000l., and under the will of the late Mr. J. L. Bowes the University would receive a legacy of Soool. for the benefit of the department of chemistry and other purposes. The company subsequently proceeded to the new electrotechnical laboratory, and Sir Joseph Swan formally opened the building, which he described as eminently suited for the purpose for which it was intended. The cost of the laboratory has been defrayed by a sum of 12,000l., drawn from the university fund, and the Lancashire County Council has contributed 1000l. towards meeting the more pressing demands for equipment.
June 8.-"On the Application of Statistical Mechanics to the General Dynamics of Matter and Ether." By J. H. Jeans. Communicated by Prof. J. Larmor, Sec.R.S. The object of the paper is to apply the methods of statistical mechanics to questions connected with radiation and the energy of the ether. An attempt is made to examine whether or not the modern theory of thermodynamics of radiation can be regarded as resting on sound dynamical principles. The result arrived at is that the use made of the second law of thermodynamics in this theory, in particular in the proof of Stefan's law, is one which cannot be justified, and hence that those parts of the theory of thermodynamics of radiation which are based upon the use of the second law must be regarded as unsound.
The problem is obtained in its simplest form by considering either a finite universe, or else a finite portion of an infinite universe, enclosed within a perfectly reflecting boundary. Let the number of degrees of freedom of the matter inside this boundary, neglecting the interaction with the ether, be N, so that there are 2N coordinates of the aggregate system which very nearly represent motion of matter only. The number N is known to be actually finite, although it may be supposed to be so large that the error involved in treating it as infinite will be negligible. Let the number of degrees of the ether be M, giving 2M coordinates to the aggregate system. If we suppose the
ether to have an absolutely continuous structure, the number M will be absolutely infinite.
The energy of the 2M coordinates of the ether is expressible as a sum of 2M squares. The energy of the 2N material coordinates may, again neglecting small terms, be divided into kinetic and potential energy. The kinetic energy is expressible as a sum of N squares, namely, the sum of the three components of energy of each electron of which the matter is composed. Thus the total energy is expressible as the sum of 2M+N squares, plus an unknown potential energy of electrons. It now follows, as in the proof of the well known theorem of equipartition of energy, that after an infinite time the sum of any of these squares stands to the sum of the remaining q squares in a ratio which is equal to piq, subject only to the condition that p and q are large enough to be treated as infinite without appreciable error. Since 2M and N satisfy these conditions, it follows that the system tends towards a state in which the energy of the ether is infinite in comparison with the kinetic energy of the matter. In other words, there is a general tendency for the ether to gain energy at the expense of matter.
It is, however, obvious that our own universe is at present far removed from its final state, so that the study of this final state is of less interest than the study of the stages through which the final state is being reached.
In discussing the transition to the final state, a principle proved elsewhere ("The Dynamical Theory of Gases,' chapter ix.) is of service. Suppose that a vibration of any dynamical system is influenced by an external agency. Then the principle in question asserts that the ultimate effect of this influence is infinitesimal, except when the external agency changes to a considerable extent in a time comparable with the period of the vibration. If the time of change in the external agency is n times the period of the vibration, where n is large, then the ultimate change in the energy of the vibration vanishes to the same order as e-n, a quantity which soon becomes negligible as n increases.
Thus, if is some small interval of time, so small that the material system may be regarded as perceptibly unaltered through a time, then the change produced in the energy of ether vibrations of which the period is less than will be very slight. The energy of such vibrations may therefore be treated as though it were incapable of change, so long as our consideration of the system does not extend over a very long period.
The total number of modes of vibration of any enclosed or unenclosed piece of ether is, as has been said, either very great or infinite, but the number of vibrations of an enclosed piece of ether of which the frequencies are below an assigned value is finite. Thus, we can now suppose M replaced by some small number M', and the value of M' will be finite. So long as we limit our consideration of the system to a finite time, say a million years, we may regard the energies of the remaining modes of vibration as constant and very small. The ratio of ethereal to material kinetic energy is now 2M'/N, a quantity which cannot be infinite and may be very small.
If is a small time satisfying the conditions specified, then the rate at which an ether vibration of high frequency gains energy will involve a factor e-, so that the time required for the vibration to acquire a perceptible amount of energy will involve a factor e. This is, of course, only true when pe is large. The energy of those vibrations for which pe is not large is rapidly adjusted, and a state will soon be reached in which these vibrations have the share of energy allotted to them by the theorem of equipartition of energy. With the progress of time the energy of the remaining vibrations gradually becomes perceptible, until ultimately the final state is reached.
We cannot however, realise in nature the boundary impervious to all forms of energy, so that it is important to consider whether these predictions have to be modified if the boundary, instead of being perfect, is simply as perfect as we can make it.
It is found that there is no longer any tendency for the energy of the matter, even after infinite time, to vanish in comparison with that of the ether inside the enclosure; the two tend to assume a finite ratio, although neither of the actual energies can be permanent, as the system
inside the enclosure is no longer a conservative system. This definite ratio between matter and ether, however, lends a meaning to the expression "radiation at a given temperature, at any rate so long as we are concerned with the same enclosure and the same enclosed matter.
Stefan's empirical law states that the radiation is proportional to the fourth power of the absolute temperature, and Bartoli and Boltzmann have attempted to raise the law to the level of a theoretical law.
Their argument rests fundamentally upon the application of Carnot's principle to the working of a heat engine, in which the working substance is the ether.
Carnot's principle is, in effect, identical with the second law of thermodynamics, and this in turn is a special case of a special proposition in statistical mechanics. In the present investigation the most general methods of statistical mechanics are used, and the conclusion arrived at is different from that of the second law. The general investigation ought, of course, to take precedence over the attempted extension of the special case. It is, moreover, easy to find the exact point at which the general argument parts company with that used in the special case. In the special case, we are dealing only with forms of material energy such that there is an easy and rapid transfer of energy to the final state. The increase of entropy indicates simply the tendency to move towards this final state, and Carnot's principle is seen to be a special case of this general tendency in which it is supposed that the working substance is at every instant in the final state appropriate to its energy at that instant. When the ether is in question, it is found that the transfer of energy to vibrations of short wave-length, instead of being infinitely rapid, is, in point of fact, extremely slow, so that we never have to deal with a final state at all.
Moreover, it has to be assumed for Bartoli's argument that the energy of the working substance is a function of only two independent variables, e.g. the temperature and the density. This is not true in the case of an engine in which ether is the working substance; the ether energy is the sum of a number of vibrations of different wavelengths, and the number of vibrations which have to be included in this sum will depend on the nature as well as on the temperature of the matter with which the ether is in communication.
Again, in the proposed argument for Stefan's law, the piston of the pump forms a moving boundary for the ether. The action of such a pump would change the frequency of vibrations in the ether, and energy which at one instant belonged to a vibration of one period would, after passing through the pump, belong to a vibration of some entirely different frequency. The energy of the vibrations of high frequency no longer remains unaltered and very small, for there is a transfer of energy to these vibrations at every stroke of the pump. The system will rapidly assume the final state appropriate to the value of this total energy, and this is a state in which the energy of matter vanishes in comparison with that of ether. Thus Bartoli's proof might be applicable to a universe in which pumps of the kind assumed had an actual existence, but has no application to cur own universe in which the vibrations of highest frequency do not come into play at all.
It now appears that in attempting to obtain a law of radiation in conformity with the analysis of the present paper, we shall not be able to use any method so general as that of the second law of thermodynamics. The whole question is not one of partition of energy, but of transfer of energy.
"The Microsporangia of Lyginodendron." By R. Kidston, F.R.S.
In a preliminary note a description was. given of the microsporangia of Sphenopteris (Lyginodendron) Höninghausi, Brongt. It had been thought by some that the Telangium Scotti, Benson, might be the microsporangia of Lyginodendron, but the discovery of sporangia possessing all the characters of Crossotheca, Zeiller, in organic connection with the sterile foliage of Lyginodendron (Sphenopteris Höninghausi) shows that Telangium Scotti must belong to another plant.
The members of the genus Crossotheca (of which several
species are known) had previously been regarded as true jerns, but now they must be classed with the Pterido spermeæ. The barren foliage of the species included in Crossotheca is very varied, and though the majority of the species possess sphenopteroid pinnules, one at least bears pinnules of the pecopteroid type.
In Sphenopteris (Crossotheca) Höninghausi each "fertile lobe bore six to eight broadly lanceolate sharply-pointed microsporangia. In the early condition the sporangia are bent inwards, and form a small hemispherical bunch with their apices meeting in the centre. At maturity the sporangia spread outwards, when they appear as a fringe hanging from the margin of the fertile pinnule, but are in reality connected for some distance to its lower surface. The microsporangia are bilocular, the parallel loculi being only separated by a narrow band of tissue. Dehiscence took place by a longitudinal cleft which passes down the inner surface of the sporangium in the line of the dividing wall of the two loculi."
The figure shows a penultimate pinna enlarged two
times. The ultimate pinna c and d bear sterile pinnules at their base, above which are some fertile pinnules. These latter, however, are better seen at e.
It has previously been shown by Prof. Oliver and Dr. Scott that the seed of Sphenopteris Höninghausi is the Lagenostoma Lomaxi of Williamson. Sphenopteris Höninghausi is thus the first pteridosperm of which the male and female organs are known.
The specimens described were derived from the 10-foot Ironstone-measures, Coseley, Dudley, which belong to the Westphalian series of the Coal-measures, and were communicated to the author by Mr. H. W. Hughes.
Royal Microscopical Soci ty, June 21.-Mr. G. C. Karop, vice-president, in the chair.-Dr. Lazarus-Barlow exhibited and described a new form of warm stage, devised by him, that could be heated by oil or gas.-Mr. Cecil R. C. Lyster exhibited an improved form of warm stage. heated by electricity.---Mr. C. L. Curties exhibited an arrangement for obtaining dark ground illumination with high powers, which had been suggested to him by a contrivance made by Leitz for attaining this object. He showed Pleurosigma angulatum on a dark ground under a 1/12-inch oil immersion objective. Mr. Rheinberg directed attention to an experiment showing that the ap