Metagymnospermæ consisting of the Conifers and Guetales. It is well point out that Ginkgo forms a link between the two main divisions. The long chapter on Coniferales is chiefly devoted to an exposition of the author's well-known view of the primitive position of the Abietineæ, and especially of Pinus, and the derivation of the ancient Araucarineæ from that group. This hypothesis is maintained with great ingenuity, in the face of much inherent improbability. The opposite view of the direct derivation of the Araucarineæ from their immediate Paleozoic predecessors, the Cordaites, has been considerably strengthened by the work of Boyd Thomson and Burlingame. The view, maintained by Wieland and his followers, of an affinity between the Bennettitales and the Angiosperms, is rejected. In this connection it may be pointed out that we have no actual proof that fertilization in Bennettites was by spermatozoids, as the author assumes. The chapter on Herbaceous Dicotyledons is important, for it sets forth in detail the author's theory of their derivation from arboreal ancestors, a view which is well worthy of consideration. The author believes that the fresh and vigorous herbaceous vegetation will tend in future to supplant the forest trees; he has no such hopes, however, for the Monocotyledons, which he acutely remarks (p. 198), may be said to represent the second childhood of the vascular plants. "This group seems to have reached such a high degree of specialization that it will probably in the long run entirely disappear and be replaced by new derivatives of the still plastic dicotyledons" (p. 416). Such a consummation, however, is not likely to be reached while man remains dominant. In the chapter on anatomical structure and climatic evolution, the question of annual rings is considered. While the author finds no such rings in Cordaitean wood from Prince Edward Island (Lat. 46° 30′) he believes that they are present in contemporary wood from Lancashire (Lat. about 53° 30′). The difference of latitude seems too small to be signi ficant, and most appearances of annual rings in Carboniferous woods from any source are fallacious. Chapter XXXI. is on a special subject, the evolutionary principles exhibited by the Compositæ, and is chiefly concerned with the somewhat narrow question of the distribution of oil-canals. The concluding chapter is on anatomical technique, including the sectioning of coal and photomicrographic methods. On all these subjects the author is an acknowledged expert, and his counsels will be of the greatest value to practical workers. The index might perhaps have been made fuller with advantage. No references are given in the book; the accumulation of references often becomes a burden, but a few would have been of service to the reader as a guide to his future studies. In the present notice, attention has often been directed to points which seem open to criticism, or on which there is much difference of opinion. These divergences of view in no way detract from a high estimate of the great interest and complete originality of Professor Jeffrey's remarkable work. The illustrations, as one would expect in a book by this author, are abundant and excellent. SPECIAL ARTICLES D. H. S. ON THE SERIES IN THE ULTRA-VIOLET FLUORESCENCE OF SODIUM VAPOR IN two papers1 published by Professor J. C. McLennan an account of the extension of Professor Wood's iodine vapor spectrum into the ultra-violet is put forth. Professor McLennan has not only proved that the resonance spectrum can not be obtained in the violet, but has also proved "that we have to do here with a case of ordinary fluorescence where Stokes's law is followed and where fluorescence is stimulated by the light from any one of a number of wave-lengths of a limited portion of the spectrum." In this case the fluorescence spectrum begins at 14600 and extends to 2100, 1 J. C. McLennan, Proc. Roy. Soc., LXXXVIII., p. 289; XCL., p. 23. 4700 H while the absorption region begins at A2100, has a maximum between 2000 and 1900 and extends to 1800. The uranyl salts can also be stimulated by light of a wide range of wave-lengths and in the main Stokes's law is followed, although the fluorescence and absorption regions overlap. Like Professor McLennan's spectrum, the spectra of the uranyl salts appear to be unaffected by the mode of excitation, and while both spectra have been carefully tested for resonance, both have failed to show the phenomenon. For the above reasons it was thought that possibly the spectrum of the iodine vapor could be resolved into series of the same simple type as those found in the uranyl salts. If the wave-lengths of Professor McLennan's bands are converted into frequency numbers and plotted it is easy to discover series having constant intervals. Spectrum No. 1 in Fig. 1 shows the bands without any attempt at classification. It will be noted that the spectrum is in two sections because of its great length. Professor McLennan notices several groups of bands which are spaced approximately 20 units apart. Such groups are present at 1/λ=2400 and at 1/λ=3100, but the series designated in spectrum No. 2 of Fig. 1 possesses much longer intervals. In this plot the members of the same series are given the same letter, and in addition a few have also been designated by long brackets. Such series as A, V, N and M are given brackets and the average value of the interval placed over the bracket. Here, as has so often been observed in the study of the uranyl spectra, a given series has a constant interval, but the various series have slightly different intervals. The value assigned to series A is 160, but this is an average value for the series, the actual intervals being given under Series A in Table I. as varying between 161 to 159 units. If the reader inspects the other series he will observe that the differences are generally unequal, but show no systematic deviation from a mean value. There are a few gaps in the series which may be caused by the presence of an exceedingly strong mercury line in the region = and 1/λ There appears, however, to be an entirely In Table II. is given the frequency numbers of the mercury centers with the appertaining fluorescence bands, as well as the differences in frequency between bands and mercury center. Positive differences indicate that the bands are of smaller frequency and negative differences that the bands are of larger frequency than the frequency of the center. Although it is evident that the pairs are not always equally spaced about the centers the errors are no greater than those observed in the first method of classification. The mercury line or pair of lines which serves as a center is generally a fairly prominent line in a group of mercury lines, an exception being the first center, 1/λ=2287, or λ=4372, which is a dim satellite of λ=4359. It is of interest to observe, in comparing the PHYSICAL LABORATORY OF CORNELL UNIVERSITY, THE AMERICAN ASSOCIATION FOR SECTION G-BOTANY THE only meeting of Section G for reading of papers took place at 2 P.M., Saturday, December 29, 1917, at the school of applied science, Carnegie Institute as a joint session with the Botanical Society of America and the American Phytopathological Society. The program consisted of the Vice-Presidential address followed by a Symposium on War Problems in Botany as outlined in the printed program. Dr. Bailey was prevented by war work from presenting his paper on the National Research Council. Dr. Coulter was not present, but his paper was read by Dr. H. C. Cowles. Dr. Smith was not present and his paper was not presented. At the business meeting following the reading of papers, D. T. MacDougal was elected member of council, R. A. Harper member of Sectional Committee for 5 years and A. B. Stout member of general committee. It was moved and carried that a committee be appointed by the chair to report to a later business meeting of the section on two considerations: (a) The organization of American botanists to forward the project of a pathological survey as suggested in the invitation paper of Dr. G. R. Lyman; (b) the possibility of assignment of drafted men of technical training and ability to scientific work of national importance and a recognition in some way that they are engaged in war service. The committee appointed by the chair consisted of G. R. Lyman. L. H. MacDaniels and C. L. Shear. It was moved and carried that the business meeting adjourn till 9 A.M. Monday, December 31. At the meeting of the Sectional Committee, December 29, the following members were present: Gager, Livingston, Blakeslee, Selby, MacDougal. Newcomb. Bartlett. Cook, Shear. A. F. Blakeslee was nominated for vice-president of the section for the ensuing year and Mel T. Cook for secretary for five years. At the request of a group of botanical editors the president and secretary of the section met with representatives from other botanical organizations to make plans for the publication of a journal of botanical abstracts. At the business meeting 9 A.M., Monday, December 31, the committee on war activities of botanists reported resolutions which were adopted. These have already been placed in the hands of the permanent secretary. A request was received from the organization committee of Botanical Abstracts for the election of two representatives from Section G on the board of control of Botanical Abstracts. B. T. Livingston was elected representative for four years and A. F. Blakeslee representative for two years. A. F. BLAKESLEE. Secretary AMERICAN MATHEMATICAL SOCIETY THE twenty-fourth annual meeting of the society was held at Columbia University on Thursday and Friday, December 27-28, 1917, extending through two sessions on Thursday and a morning session on Friday. The attendance included fortysix members. Professors R. G. D. Richardson, of Brown University, and J. W. Young, of Dartmouth College, presided. The council reported the election to membership in the society of Dr. J. W. Campbell, Wesley College, Winnipeg; Dr. Mary F. Curtis, Western Reserve University; Mr. C. H. Parsons, Columbia University; Mr. J. B. Rosenbach, University of New Mexico; Mr. H. M. Terrill, Columbia University. Five applications for membership were received. Committees were appointed to arrange for the summer meeting of the society at Dartmouth College in 1918 and for the summer meeting and colloquium at the University of Chicago in 1919. The total membership of the society is now 735, including 77 life members. The total attendance at all meetings, including sectional meetings, during the past year was 338. The number of members attending at least one meeting during the year was 198. At the annual meeting 116 votes were cast for officers. The Treasurer's report shows a balance of $9,762.98, including the life membership fund of $6,333.13. Sales of the society's publications during the year amounted to $1,474.19. The Library now contains 5,475 volumes, excluding unbound dissertations. At the annual election, which closed on Friday morning, the following officers and other members of the council were chosen: Vice-presidents, J. L. W. B. Carver: "The conditions for the failure of the Clifford chain."' C. J. Keyser: "The role of the concept of infinity in the work of Lucretius." C. J. Keyser: "Concerning the number of possible interpretations of any system of postulates."' W. H. Wilson: "Systems of functional equations which define hyperbolic sine, hyperbolic cosine, sine and cosine uniquely.”’ C. H. Forsyth: "Tangential interpolation of ordinates among areas. "" W. B. Fite: "Concerning the zeros of the solutions of certain differential equations. "" R. L. Moore: "Concerning a set of postulates for plane analysis situs.'' C. A. Fischer: "Integral equations involving Stieltjes integrals.'' O. E. Glenn: "Preliminary report on a new treatment of theorems of finiteness.'' C. L. E. Moore: "Rotations in hyperspace."' G. M. Green: "Memoir on the general theory of surfaces and rectilinear congruences." J. F. Ritt: "On the iteration of rational functions.'' Olive C. Hazlett: "On rational integral invariants and covariants of the general linear algebra." Anna J. Pell: "Systems of linear equations.'' Norbert Wiener: "Internal isomorphisms of complex algebra.' |