maturity. In my judgment it is clearly the duty of the state to adjust taxation on growing stands of timber, provide adequate protection against fire and other destructive agents, instruct the public in silvicultural methods and encourage reforestation by providing planting stock. In return for this assistance by the public, forest land must by law be subject to public regulation which will insure regrowth of acceptable species. Furthermore this public regulation must be in the hands of local boards whose function it is to interpret the requirements of the law in their particular locality. Constructive state forest legislation is only in its beginning. It is your duty and mine to assist in every way we can in making regrowth possible. First, as American citizens and voters we should work for increased publicly owned forests by the nation, by states, and by local communities. Second, as American citizens and voters we should work for the reasonable public regulation of all forest lands, based upon a system of cooperation between the public and the private owner that will make regrowth possible without, in the long run, entailing financial loss upon the owner. Third, as American citizens and voters we should work for more liberal financial support of the entire forestry movement by both the nation and the state. THE SCHOOL OF FORESTRY, YALE UNIVERSITY J. W. TOUMEY OCCURRENCE OF PLEISTOCENE VERTEBRATES IN AN ASPHALT DEPOSIT NEAR MCKITTRICK, CALIFORNIA PLEISTOCENE mammalian remains from asphalt deposits located along the southwestern border of the Great Valley of California have been known since 1865, when Joseph Leidy reported the occurrence of two horse teeth from near Buena Vista Lake and referred the specimens to Equus occidentalis. Further remains of this species from the region of Buena Vista Lake were described and figured by Leidy1 in 1873. Thirty years 1 Leidy, J., Proc. Acad. Nat. Sci. Phila., 1865, later J. C. Merriam2 described a fragmentary lower jaw of the dire wolf, Enocyon dirus, that apparently came from an asphalt bed in Tulare County, California. The construction of the Taft-McKittrick highway in the petroleum producing belt southwest of Bakersfield has brought to light a fossiliferous bed of asphalt on the southern outskirts of the town of McKittrick. The deposit is apparently located in a narrow zone of asphaltic material shown on the geologic maps of the McKittrick oil region as traversing the foothill region immediately southwest of McKittrick. As mapped by Arnold and Johnson this brea belt is associated areally with Pliocene and Miocene marine beds and is found also in contact with the alluvium of McKittrick Valley. The occurrence of bones in asphalt near McKittrick was known for many years to the Department of Palæontology of the University of California. Recently John B. Stevens explored the deposit and secured a number of specimens that were kindly presented to the University. During the past summer a field party from the Museum of Paleontology with cooperation and support of the Carnegie Institution of Washington, commenced excavations and made additional collections. Grateful acknowledgment should be made to the Midway Royal Oil Company for permission to excavate and for valuable assistance rendered during the progress of the work. In the brea deposit near McKittrick a surface stratum of hardened asphaltic material reaches in places a thickness of several feet. This layer contains numerous remains of birds and mammals, apparently representp. 94; Rept. U. S. Geol. Surv. Terr., pp. 242-244, pl. 33, fig. 1, 1873. 2 Merriam, J. C., Univ. Calif. Publ. Bull. Dept. Geol., Vol. 3, pp. 288-289, pl. 30, fig. 2, 1903. 3 Arnold, R., and Johnson, H. R., “ Preliminary report on the McKittrick-Sunset Oil Region, Kern and San Luis Obispo Counties, California," pl. 1, U. S. Geol. Surv. Bull. 406, 1910; Pack, R. W., "The Sunset-Midway Oil Field, California, Part I., Geology and Oil Resources,'' pl. 2, U. 8. Geol. Surv. Prof. Paper 116, 1920. ing the Recent fauna, and overlies the deposit in which Pleistocene vertebrates are found. In excavating the older bed dense accumulations of mammalian remains were encountered. This deposit is in general comparable to these occurring at Rancho La Brea. The exhumed material was, however, not so well preserved as that from the asphalt bed near Los Angeles. This seems due, in a measure, to a prevailing earthy matrix showing somewhat less impregnation by petroleum than in the Rancho La Brea beds. A small collection of bird remains from the McKittrick deposit was submitted to Dr. L. H. Miller for examination. A preliminary statement has been kindly given by Dr. Miller as follows: 1. Of the ten species thus far determined, six are aquatic or semi-aquatic in habit. With more careful examination to determine exact identity of ducks and waders, this proportion will be increased. Quite the reverse is true of the Rancho La Brea beds. 2. The golden eagle (Aquila chrysaëtos) is the most abundant species of land bird. One hawk (Circus), one caracara (Polyborus), and two falcons (Falco sparverius and F. near fuscocerulescens) are the only other raptors. No owls or vultures appear in the collection. 3. Parapavo is not represented. A single quail bone represents the great group of Gallinæ. 4. Shore birds (Limicolæ), so rare in the Rancho La Brea beds, are very abundant here. More specimens of this group are present in the collection of 100 specimens from McKittrick than in all the 50,000 examined from Rancho La Brea. 5. So far as examined there appear no extinct or extra-limital species not found at Rancho La Brea. On the other hand Teratornis, Parapavo, the great list of condors, vultures, eagles, old world vultures, and owls are thus far lacking. 6. The caracara, the indeterminate falcon, and the two storks, Ciconia and Jabiru, give the same suggestion of semitropic climate as in the case of Rancho La Brea. Following is a provisional list of the Pleistocene mammalian fauna known from the McKittrick locality: Enocyon dirus (Leidy) Canis, near ochropus Esch. Felis atrox Leidy Felis, near daggetti Merriam Equus occidentalis Leidy Bison, sp. Camel, slender limbed form Mastodon, sp. Several of the mammalian species listed above are known from Rancho La Brea. The dire wolf (Enocyon dirus), the great lion (Felis atrox) and the horse (Equus occidentalis) also occur in the asphalt beds near Los Angeles. Machaerodont cats have not been recognized at the McKittrick locality. The bear (Arctotherium) and the ground sloth (Mylodon) occur in both deposits, although the forms represented at McKittrick may be specifically separable from the types found at Rancho La Brea. A camel with slender limbs is certainly distinct from the large Camelops hesternus found at Rancho La Brea. Further collecting at the McKittrick locality will bring out the relationship between this assemblage and the Rancho La Brea fauna. The contrasting features that are recognized at present may result from a geographic separation of the two asphalt deposits. It is probable that the environmental conditions prevailing in the southern portion of the Great Valley of California during the Pleistocene were somewhat unlike those existing in the vicinity of Rancho La Brea. On the other hand, it may be that the faunal differences are to be interpreted as indicating separate stages of the Pleistocene. JOHN C. MERRIAM, CHESTER STOCK SPECIAL OIL-IMMERSION OBJECTIVES FOR DARK-FIELD MICROSCOPY DARK-FIELD microscopy was introduced by Joseph Jackson Lister in 1830, and by the Rev. J. B. Reade in 1837. The optical principles were clearly enunciated by F. H. Wenham in 1850-1856, and apparatus substantially as now employed was made and described by him for use with high powers. In 1877 Dr. James Edmunds constructed special paraboloid condensers for dark-field work with high powers, and insisted upon the necessity of a homogeneous contact of the top of the condenser and the lower face of the microscopic slide, and that the slide should have a thickness corresponding to the focus of the condenser. He recommended this means of study for the body fluids like blood, etc., and for the investigation of living bacteria, whose appearance and actions were described by him in a most striking and picturesque manner. This information was published in some of the most important and widely distributed English publications (Transactions of the Royal Society, 1830, Trans. Micr. Soc. of London, and Quart. Jour. Micr. Science, 1850-1856; Jour. Quek. Micr. Club, and Month. Micr. Jour., 1877; Quekett's "Treatise on the Microscope," 1848-1855, and Carpenter's "The Microscope and its Revelations," 1856). In spite of this wide publicity the darkfield microscope was used very little either in biology or in medicine. After the discovery in 1905 of the microbe of syphilis, and that it could be demonstrated in the living state with the dark-field microscope, this method of investigation became of vital importance to medical men; and that importance has increased rather than diminished in recent years. It seems to the writer that it is of equal if not greater importance to the biologist, the physiologist, and the clinician for the examining of the body fluids in health and disease and in the study of living microorganisms, for it brings out with the greatest clearness structures and details of structure invisible in the bright-field microscope. It thus renders the absolute dependence on staining agents after various fixing materials have been used no longer necessary, and serves as a check to the appearances sometimes given by these agents. Dark-field microscopy has two requirements that must be met for its successful use as was pointed out by the early investigators with it: (1) a very brilliant light is needed. Full sunlight was recommended and remains the most satisfactory light, although the newly devised electric lights like the small arc lamp and the low-voltage head-light lamps serve very well. (2) The other difficulty that must be overcome is the large aperture of high-power objectives, especially those of the immersion type. This is because the dark-field condensers can not be constructed with high enough aperture to give a dark-field with these highpower objectives, and they are a necessity with the most exacting work. Two courses were open with the high powers: (a) To so construct them that the aperture was low enough to give dark-field effects with the dark-field condensers practicable to construct, and (b) To introduce into the high apertured objectives a diaphragm that should cut down the aperture. The second course was adopted, and reducing diaphragms of all kinds with apertures varying from 0.40 to 0.90 N. A. have been met with; and in a few cases those as low as 0.20 N. A. were found. Not only was there great variation in the aperture of the reducing diaphragms for the oil-immersion objectives, but in many cases they were so constructed that they were liable to get out of place, get out of the optic axis, and prove generally unsatisfactory. Unfortunately also some of the workers in the pathological field were trying to use oil-immersion objectives for dark-field work with no diaphragm at all, and of course could get no dark-field effects. After a full examination of the different dark-field condensers made in our own country and abroad, it seemed to me that the best all around aperture for the objective to use with them would be about 0.80 N. A. Such an aperture will give a good dark field with all the standard dark-field condensers, and this aperture is great enough to give good resolution on the one hand and the needed brilliancy on the other. I appealed to the American manufacturers of microscopic objectives to design and manufacture oil-immersion objectives of this aperture (0.80 N. A.). With such an objective the worker either in biology or in medicine can get good results even without a very profound knowledge of the optical principles involved. He can also go forward with his work with full confidence that the objective being used will give good results, and every worker knows the importance of confidence in his apparatus for successful accomplishment. Finally, during the past summer and autumn the Bausch and Lomb Optical Company of Rochester, N. Y., undertook the manufacture of the desired medium-apertured oil-immersion objectives. The outcome is all that could be asked; and they have been subjected to the most rigid tests in actual practise in the fields in which darkfield work is applied. These objectives are now available, and the writer feels confident that every one using them will feel grateful for the freedom from worry that was always involved in modifying a high-apertured objective for the dark field. agree It is only fair to add that no matter how enthusiastic one may be over the possibilities of dark-field microscopy, much more skill is necessary in it than for the ordinary brightfield microscopy. I think that all who have used the dark-field microscope successfully will that the ideal plan for an individual or for a laboratory is to have a microscope devoted to this work alone. If then a proper electric light is available, one can proceed to make examination of specimens with the dark-field microscope with the same certainty and rapidity with which examinations are made with the bright field. It may be stated in passing with reference to these new objectives, that they have certain advantages for ordinary bright-field work. As ordinarily employed the oil-immersion objectives of high aperture (1.40 to 1.20 N. A.), are used in bright-field work without oil-immersion contact between the under surface of the slide and the top of the brightfield condenser. As light of an aperture greater than 1.00 N. A. can not emerge from the condenser into air, it follows that not nearly all of the available aperture is employed. It was believed there THE INTERNATIONAL GEOLOGICAL CONGRESS COMMITTEE AT the twelfth session of the International Geological Congress, the president was instructed to nominate a committee to consider the question of a permanent constitution and to submit a proposal thereon to the next session of the Congress. The following committee was appointed: R. W. Brock, President; J. S. Anderson, C. Barrois, A. Karpinsky, A. Renier, Geo. Otis Smith, G. Steinmann and E. Teitze. The committee met in the rooms of the Geological Society of London on July 20, 1921. There were present: R. W. Brock, President; A. Renier, Geo. Otis Smith and F. D. Adams (ex-officio member). At a preliminary conference called to obtain for the guidance of the committee the opinion and advice of a wider and more representative body, the following resolution had been passed: That this meeting is of opinion that the question of the establishment of an International Geological Union should be considered at the next International Geological Congress, and that it is undesirable that any steps should be taken until the question has been so considered at a full and representative gathering of geologists. A concise proposal with regard to a constitution to submit for the consideration of the next International Geological Congress was drawn up, the main points of which are as follows: The purpose of the International Geological Congress, it was stated, is to advance scientific investigations relating to the earth from the point of view of pure geology as well as of its application to the arts and industries. The sessions of the Congress are called every three or four years, to continue for about one week. At each session, invitations will be received and the meeting place of the next session determined by the Congress. Excursions constitute an important adjunct to the sessions and every possible facility is given to the members to study the geologic structure of the country where they are assembled, and of its mineral resources, at a minimum expense and under the direction of the most competent guides, with guide books specially prepared which serve the double purpose of guiding the excursionists and of presenting a general review of the geology of the country in which the Congress meets. Standing committees are organized for the purpose of handling questions of general or international interest demanding international collaboration, and the Congress may award prizes founded for meritorious work within the domain of geologic research. The organization should be simple and include: A Committee of Organization, appointed by the host nation, will arrange for that session, its programs and excursions, and its publications. Officers. At the first general meeting of the session, the Committee of Organization shall submit nominations for President and Secretary of that session, and the Council shall submit nominations for Vice-President, for elections by duly accredited members. Council.-The Congress is administered during its sessions by a Council made up of 1. Members of the Committee of Organization for that session. 2. Presidents of Geological Societies. 3. Directors of national and other large geological surveys. 4. Officers elected by the members of the session. The Council will prepare the order of the day for the meetings. Standing Committees.-These Committees may be appointed by each Congress to report at the next session, and will be responsible to the Committee of Organization for that next session for the preparation and submission of their reports. Membership.-Invitations to each session of the Congress are issued by the committees representing the host nation, to recognized geological organizations, universities, and to national gov ernments. Membership in the Congress is generally restricted to geologists of national standing. Tenure of Office.-The Committee of Organi zation and officers shall hold office until the close of that session, or until the next committee of organization is formed, to which the documents and files of the Congress shall be transferred. Subcommittees of the local committee shall continue to function until the publications of the session are issued or other business concluded. The President of the Congress shall, however, preside at the opening meeting of the next session of the Congress, resigning the chair when his suecessor is elected. SCIENTIFIC EVENTS MOLDING SAND RESEARCH HUNDREDS of thousands of tons of molding and core sands are used annually in the iron, steel and non-ferrous foundries of America A little of it is re-used; much more might be. Sands are not always correctly selected for specific purposes. Mixing and other treatment can secure improvement. In what ways can foundry practise as to sands be bettered? What economies can be realized, not only in reduced expenditure for sand, but also in less number of lost castings and higher quality of accepted product? Last spring, the American Foundrymen's Association decided that thorough study of this subject would be profitable and asked the cooperation of the American Institute of Mining and Metallurgical Engineers. The Institute referred this request to the Division of Engineering of the National Research Council, of which it is a member. Through joint action with the division a valuable digest of the literature has been made by Professor Robert E. Kennedy, of the University of Illinois, and a large committee of foundrymen, engineers and scientific men has been selected, under the general direction of President W. R. Bean, of the Foundrymen's Association and the chairman of the division. This committee on molding sand research has just been organized with the following officers and executive committee: Chairman: R. A. Bull, consulting engineer, Sewickley, Pa. |