19, No. 10, pp. 317-334, one plate, two textfigures. February 13, 1920. Professor Kofoid, the leading student of the Flagellata, in a brief but important paper, discusses convincingly the morphology and relationship of Noctiluca. The data and their bearing are well indicated in the author's summary, as follows: 1. Notiluca is a tentacle-bearing dinoflagellate with a sulcus, girdle, and longitudinal and transverse flagella. 2. The sulcus is longitudinal and midventral. It includes the apical trough and the recessed oral pouch and cytostome. 3. The tentacle arises from its posterior end. 4. The girdle has hitherto been overlooked. It is a shallow trough at the left of the sulcus and at right angles to it. It is seen best in small individuals. 5. The longitudinal flagellum is reduced and lies within the oral pouch. The transverse flagellum is represented by the prehensile tooth at the proximal end of the girdle at the left of the base of the longitudinal flagellum. This organ exhibits structural undulations and spasmodic or rhythmical contractions. 6. Distention by hydrostatic vacuoles, with flotation replacing active locomotion, has led to degeneration of the flagella and their reduction in size, and to the almost complete disappearance of the girdle. 7. Noctiluca belongs in the Noctilucidæ, a family of the tribe Gymnodenioidæ, with Pavillardia, another tentaculate, naked, non-ocellate dinoflagellate. 8. There is no morphological justification of a separate order of flagellates to hold Noctiluca, such as the Cystoflagellata Haeckel. 9. The Cystoflagellata may be retained as thus emended to receive Leptodiscus and Craspedotella pending discovery of their affinities. MAYNARD M. METCALF THE ORCHARD LABORATORY, OBERLIN, OHIO SPECIAL ARTICLES THE EFFERENT PATH OF THE NERVOUS SYSTEM REGARDED AS A STEP-UP TRANSFORMER OF ENERGY THE properties of nervous tissue which fit it for its peculiar rôle in the animal economy are given by Sherrington as (1) excitability (2) spatial transmission of impulses and (3) control of the liberation of energy in contiguous tissues. Pawloff and others have emphasized the rôle of the peripheral sense organs as energy transformers, since the energy of light or heat or sound is transformed, by appropriate mechanisms, to the energy of a nerve impulse. Lucas and Adrian's all or none hypothesis of nerve conduction calls attention to another aspect of the work of the nervous system as a transformer of energy. According to this hypothesis, the nerve impulse conducted by any single nerve fiber is at all times the maximum impulse which it is capable of conducting. The evidence in favor of this view appears to be steadily accumulating, although there are still conditions under which the energy relationships are not clear. The efferent paths of the nervous system appear to me to furnish additional confirmation of the general truth of the hypothesis. Neurologists have frequently commented on the relatively few nerve fibers in the main motor tracts of higher animals, i. e., the pyramidal tracts, as compared to the number of fibers in the ventral roots of the spinal nerves and the great mass of muscles to be activated. According to von Monakow, Redlich, Schäfer and others, fibers of the pyramidal tract do not end directly about the cells of origin of the motor nerves, but about some intermediate or intercalated cells in the spinal cord. Von Monakow has supposed that each of these intermediate cells comes into relation, through the branching of its processes, with more than one motor cell in the spinal cord. Furthermore, the axone of each peripheral motor nerve may branch on its way to its effector. There is a possibility, therefore, that each descending fiber in the pyramidal tract of the spinal cord may ultimately be able to actuate several terminal axones in the peripheral motor system. Suppose that one pyramidal fiber may, through the intercalated neurone, come into relation with three cells of origin of peripheral fibers, and that each of these peripheral fibers, in its turn, is divided into two. These relationships may be indicated diagrammatically. One pyramidal fiber may, therefore, be represented Int FIG. 1. at the periphery by six branches of axones, each of which is in its turn capable of acting upon an effector. The energy, a, coming down the first fiber in the series, Py, is, according to the all or none hypothesis, the maximum which the fiber is capable of conducting. Similarly, the energy passing over the intercalated (Int.) fiber before its branching is also the maximum which it is capable of conducting. Suppose that it is equal to a. At the point of branching, the energy conducted along each branch must either be brought up to some quantity closely approximating a, or else it must fall to a/3. In the latter case, the energy passing over the proximal unbranched portion of the fiber M must either be brought up to the value a, or else in its turn be close to the value a/3. Going on out to the bifurcation of this fiber, there must again be a raising of the energy in each of the branches to some value closely approximating a, or else it must fall to a value a/6. There is little or no evidence that the energy of the nerve impulse falls off in any such degree in its passage from central system to periphery. The presumption is, therefore, that the efferent distribution path acts as a step-up transformer of energy, although the manner of its action is as yet unknown. It should be stated here that the nerve fiber itself furnishes the energy, derived in some manner as yet unknown from its own metabolic processes, and that there is, in all probability, no change in voltage at the expense of the amperage, as in the electrical transformers with which the physicist is familiar. Reference to Ranson's1 diagram of the sympathetic system will show that the same considerations apply there. In fact, the diagram given in this paper was suggested by Ranson's diagrams. One more link in the scheme of the step-up transformer may be what Langley has called the receptive substance, interposed, chemically if not histologically, between the motor end plates and the contractile substance in muscle. It is certain that there is a great increase in the energy of a muscle contraction as compared with the energy of the nerve impulse, which, starting in the central system, finally evokes the muscle contraction at the periphery. It seems reasonable to suppose, in the light of our present knowledge, that the efferent nerve path is a part of this transformer system. Such general relationships of the energy of the response to the energy changes in the processes preceding the response have long been recognized. Balfour Stewart (p. 163) remarks: "We have seen that life is associated with delicately-constructed machines, so that whenever a transmutation of energy is brought about by a living being, could we trace the event back, we should find that the physical antecedent was probably a much less transmutation, while again the antecedent of this would probably be found still less, and so on, as far as we could trace it." We should recognize, however, that such relationships have a limit in the living organism. Otherwise, we would arrive at perpetual motion. F. H. PIKE DEPARTMENT OF PHYSIOLOGY, ON SPIRAL NEBULE ONE of the privileges of the vacation is the opportunity of making one's own tea in one's own vessels. I did so recently, aided by a deep precipitation glass, g, with a lip, l, running far down the sides. On stirring the 1 Ranson, S. W., 1918, Journal of Comparative Neurology, Vol. 29, p. 306. 2 Stewart, Balfour, 1874, "The Conservation of Energy," New York, p. 163. liquid with a spoon, energetically, and removing the latter, I noticed that a sharply outlined spiral was persistently present on the surface, until the deep paraboloid returned to the plane. My explanation would be, that at 1, part of the tangential velocity is converted into local vortical motion, whereby the particles at 7, because of the reduced centrifugal force, slide down the inclined plane of the rotating paraboloid. From another point of view, a stationary wave is produced on the surface by the interference at l. g g FIG. 1. Now though I will not venture to repeat the superscript of this note, I will nevertheless ask whether something analogous to the above simple experiment may not be taking place in astronomical space. Suppose we replace the glass vessel of the figure by a gravitational mechanism; and suppose we "lip" it at 1, by making that locality a region of effectively greater density and relatively at rest. If Kepler's law be written in the form so convenient in its present relations to the modern atom (M, being the virtual mass at the center and A the angular momentum per gram, whereby rv2 A2/r=M, for the tangential velocity v at r), then any local diminution of A in accordance with the above model, would be followed by a diminution of r in the part affected. = At all events the hydrodynamic experiment (rotational surface figures, as related to shape of boundary) is very beautiful and certainly more approachable. I shall allow myself to THE PACIFIC DIVISION OF THE AMERICAN AS- THE Seattle meeting of the Pacific Division of the American Association for the Advancement of Science held June 17 to 19 at the University of Washington, Seattle, was perhaps the most successful so far held by the Pacific Division. Sixteen affiliated societies were scheduled in the final program and delegates were in attendance from every part of the Pacific Coast area. The representation from the University of California and Stanford University was particularly large. The special sessions of the convention in which the various affiliated societies participated were well attended and the beneficial results of this cooperation were apparent. The conference of Research Committees from the educational institutions of the Pacific Coast held two sessions which were attended by all the delegates. The problems connected with the maintenance and encouragement of active research in the college and university were presented and discussed and some practical suggestions were made. It was felt that distinct progress in the solution of these problems had resulted from this meeting and that the research conference should be a permanent feature of the annual meetings of the Pacific Division. A symposium on the "Einstein Theory of Relativity" was of general interest and was also well attended. In the symposium on "The Animal and Plant Resources of the North Pacific Ocean" given under the auspices of the Pacific Fisheries Society and the Western Society of Naturalists, each speaker emphasized the great need for more knowledge of the ocean and its life to save the fisheries industry. It is hoped that the means will be found to publish the papers in this symposium as a contribution to a better understanding of the importance of the projected exploration of the North Pacific Ocean through international co operation. This project will be further advanced at the Pan-Pacific Scientific Congress to be held in Honolulu from August 2 to 20. Notable features of the meeting were the presidential address by Dr. John C. Merriam who spoke on "The research spirit in the every-day affairs of the average man" and the address by Professor R. W. Brock, of the University of British Columbia, on "The last crusade under Allenby." On account of illness, Dr. Charles E. St. John, of Mount Wilson Observatory, was unable to give the Sigma XiPhi Beta Kappa lecture. His place was supplied by Dr. Paul W. Merrill, of Mount Wilson Observatory, who spoke on "The chemistry of the stars." Dr. William E. Ritter, director of the Scripps Institution for Biological Research, was elected president of the Pacific Division for the year 1920-21. Dr. William M. Dehn, professor of chemistry, University of Washington and Dr. E. P. Lewis, professor of physics, University of California, were elected members of the executive committee to serve five years and Dr. E. C. Franklin, professor of chemistry, Stanford University, was elected a member of the executive committee to fill the vacancy caused by the election of Dr. Ritter to the presidency. The officers of the Pacific Division for the coming year are accordingly as follows: Dr. William E. Ritter, president, Scripps Institution for Biological Research, La Jolla, Calif. Dr. Barton W. Evermann, vice-president and chairman of the executive committee, California Academy of Sciences, San Francisco, Calif. W. W. Sargeant, secretary-treasurer, California Academy of Sciences, San Francisco, Calif. MEMBERS OF THE EXECUTIVE COMMITTEE Dr. Barton W. Evermann, chairman, California Dr. W. W. Campbell, Lick Observatory, Mount Dr. William M. Dehn, University of Washington, Seattle, Wash. Dr. E. C. Franklin, Stanford University, Calif. Dr. C. E. Grunsky, Mechanics Institute Building, San Francisco, Calif. Dr. T. F. Hunt, University of California, Berkeley, Calif. Dr. E. P. Lewis, University of California, Berkeley, Calif. Dr. D. T. MacDougal, Desert Laboratory, Tucson, Arizona. An amendment to the constitution of the Pacific Division was proposed in executive session held Thursday evening June 17 to exclude Arizona and the states of Chihuahua and Sonora in Mexico from the territory of the division. This action was in conformity with that taken by the National Council which has caused these states to be included in a recently organized division of the American Association. As an encouraging sign that the purposes of the annual meeting are being in some measure fulfilled it is noted that considerable publicity was given to the meeting in the Seattle papers. At least two editorials appeared on topics related to the discussions and reports of the meetings were given in some detail. This would indicate that the public is becoming more generally interested in the progress of science and augurs well for the future support of scientific investigation. Announcement was made by the executive committee that the next annual meeting would be held in the San Francisco Bay region, the definite time and place to be determined later. This location will accommodate the largest number of members and should insure a good attendance for the 1921 meeting. SCIENCE MEDICAL RESEARCH1 I HAVE said that I would not plunge with you this evening into the ocean of science; but if you are a little tired of hearing of the dependence of medicine upon science you may find refreshment or diversion in contemplating the debts of science to medicine. My old medical friend Mr. Meade, of Bradford, was almost the only man who knew much about flies at the time when Manson and Ross began to watch these little pests. Without medicine, bacteriology and the study of the cell would have made slow way; yet it is the study of the cells of bacteria, of alge, of protozoa-not of mandarins-which has brought us nearer to the secret of life. On the wonderful world of the cell I have spoken before. Professor Hopkins has lately described to us the almost incredible coexistence in it of different constitutions, phases, and events; though every change in any phase affects the equilibrium of the whole cell system. And every one of these is essential to the whole; "so long, for example, as a liver cell remains alive its glycogen constituent can not be wholly removed." If a cell be so ground up as to become more homogeneous, its reactions fall out at haphazard, and the cell dies by mutual destruction of its parts. This process of nature is illustrated on a mighty scale to-day in the disintegration of the Russian social organism. Some of the apparently simple cell constituents, hæmoglobin for instance, are incredibly complex; this substance is specific for every kind of animal; in allied species, if concordant, it is not identical. Of the chromosomes I need say nothing; except to hope that as X rays have analyzed crystalline structure some such rays may analyze nuclear constitutions. By another way, medicine has promoted research on organic syntheses; and conversely on 1 From the address of the president of the British Medical Association at the Cambridge meeting. |