may also throw some light on the nature of protoplasm in that it gives information concerning the lower limit of metabolism necessary for life.

In a series of experiments made in connection with other work on Didinium described elsewhere, it was found that the cysts live much longer than had been anticipated. On June 11, 1910, several didinia, all derived from the same individual, were put into a 100 c.c. beaker containing 50 c.c. of solution with numerous paramecia. The beaker was then placed in a damp chamber and left until January 15, 1911. At this time many didinia cysts were found in the beaker, and no active organisms except a few rotifers. It is not known just when these cysts were formed, but, judging from what usually occurs under similar circumstances, they were probably all formed within a week after the didinia had been added to the culture of paramecia, i. e., about the middle of June, 1910.

On May 31, 1911, a 10 c.c. vial was filled with solution from the beaker containing about one half the cysts. The vial was then corked, sealed airtight with paraffin and laid away in a dark drawer. The remaining cysts were added to a portion of a vigorous culture of paramecia, and the rest of this culture was retained as a control. Two days later there were several didinia in the portion seeded with cysts, none in the control, showing that the cysts were still viable. A few cysts were removed from the vial and similarly tested on each of the following dates: October 22, 1912; January 23, 1914; December 12, 1914; January 7, 1915; March 1, 1915, and March 4, 1915. In all of these tests except two, December 12, 1914, and January 7, 1915, active didinia were secured from the cysts. No didinia were found in any of the control cultures. This proves conclusively that the cysts of Didinium nasutum can live, at least, nearly five years.

In all of the tests observations were made daily. In the test of October, 1912, active didinia were found on the fifth day after adding paramecia, in those of January, 1914, on the second day, and in those of March,

1915, on the sixth and tenth days respectively.

In each of these tests, except the first two and the last, four watch glasses containing cultures of paramecia were seeded with the cysts. In the last test, March 4, 1915, all of the remaining cysts were added to two liter jars containing vigorous cultures of paramecia. In the test of January, 1914, didinia appeared in three of the watch glasses, in those of December, 1914, and January, 1915, in none, although observations were made for more than two weeks; in those of March 1, 1915, active didinia appeared in only one of the four watch glasses; but in the last test of the series they appeared in both jars. In one of these jars only a few small specimens were found and these soon died out; in the other, however, the didinia appeared to be perfectly normal; they developed rapidly and produced a vigorous culture which is still in existence, February, 1917.

It is thus evident that some of the cysts were still viable at the close of our experiment, which extended through nearly five years, but it is not clear how much longer they could have remained viable. However, at the close of the experiment the cysts were much shriveled, only partially filled with protoplasm, and yellowish in color, whereas in the beginning they were well filled with protoplasmic granules and grayish in color. Toward the close of the experiment the proportion of failures was also much larger than at the beginning. All this indicates that the cysts would probably not have lived much longer. On the other hand only a very small proportion of the cysts developed in any of the tests, probably not more than two per cent. Consequently, since the cysts became less numerous as the experiment proceeded the large proportion of failures toward the close may have been due to an insufficient number of cysts rather than to their age.

We have thus demonstrated conclusively that didinia in the encysted state can live nearly five years in a solution from which they probably get nothing in the nature of food. If the cysts are dried they probably

live even longer than they do in a solution as the results of the following series of experiments show.

Early in the spring of 1910 ten eightliter battery jars nearly full of solution containing numerous didinia were set aside in the laboratory. Eight of these jars were covered and two were left uncovered. The solution of one of these contained much débris, hay, etc., that of the other almost none. The solution in both evaporated gradually, so that on the last day of May there was only a trace of moisture left in either jar. When they were next examined early in August the debris was so dry that it could be readily crumbled between the fingers.

On January 14, 1911, one half of the solution in each of the eight jars was poured off and replaced by hay solution (1 gm. hay to 200 c.c. water boiled ten minutes), and the two empty jars were half filled with the same solution. All of the jars were then examined from time to time until February 10. Active didinia were found in only one of the jars, and this was one of the open jars, the one which contained much debris. Several active didinia were found in this jar January 17 and more later. Numerous colorless flagellates, some vorticella and also a few other forms appeared but no paramecia.

The results of these experiments, consequently, clearly indicate that the vitality of dried cysts is greater than that of wet cysts. The number of cultures tested was, however, so small that the siginficance of the results obtained is somewhat doubtful. The tests should be repeated and extended in connection with a study of the histological changes that may occur in the cysts.

S. O. MAST

THE JOHNS HOPKINS UNIVERSITY

SOCIETIES AND ACADEMIES

THE BOTANICAL SOCIETY OF WASHINGTON

THE 121st regular meeting of the Botanical Society of Washington was held in the Assembly Hall of the Cosmos Club at 8 P.M., May 1, 1917, with thirty-nine members present. Mr. Burt A. Rudolph, Mr. Glenn C. Hahn and Mr. Horace W. Truesdell were elected to membership.

The regular program was devoted to a symposium on the flora of the District of Columbia. Professor A. S. Hitchcock discussed "The plan of the flora" and traced briefly the history of the flora from Brereton's studies in 1831 to the present time. In 1906 a mimeograph list of the vascular plants was prepared by Mr. P. L. Ricker. The flora is now under the leadership of Professor A. S. Hitchcock and Mr. P. C. Standley. Twentyfive collaborators are now at work preparing the preliminary manuscript which is to be finished by June 1 and the manuscript completed by November 1, 1917.

Mr. Edgar T. Wherry, at the invitation of the society, furnished a paper on "Geological areas about Washington." The paper was read by Mr. Hitchcock. The prominent geological feature is the Fall Line which separates the Piedmont Plateau on the northwest from the Coastal Plain on the southeast. Above this line the valleys are steep-sided, and below broad and open. The Piedmont Plateau consists chiefly of crystalline gneisses of early periods, while the Coastal Plain is occupied by unconsolidated gravels, sands and clays. The soils on the Coastal Plain are acid for the most part while those on the Piedmont are not.

Mr. George E. Sudworth discussed "The distribution of trees in the floral area." Oaks predominate and constitute from one half to three fourths of the upland cover. There are about 140 species of native and naturalized trees of which the broadleaved trees number about 122 species.

"Humus as a factor in plant distribution'' was discussed by Mr. Frederick V. Coville. Mr. Coville exhibited two samples of organic matter-the one a raw, brown and leafy turf found in laurel thickets produced chiefly by the decay of the laurel leaves, and the other a black, fully-reduced, nonstructural leafmold formed by leaves high in lime content such as the tulip poplar. The former is acid and the latter alkaline in reaction.

Mr. P. L. Ricker discussed briefly the subject of "Collecting and preparing specimens."' Mr. Ricker exhibited several types of portfolios suitable for collecting plants and also suggested the use of corrugated driers and artificial heat, especially where large numbers of plants are being collected on field trips.

The program was followed by an informal discussion by Messrs. Safford, Beattie, Norton, Waite, Lewton, Shantz, Coville, Hitchcock, Sudworth and Ricker.

H. L. SHANTZ, Corresponding Secretary

FRIDAY, JULY 27, 1917

ACIDOSIS1

I

For many years students of metabolism, of general physiology and of pathology have been investigating various aspects of the acid-base equilibrium of the body, always with an eye to the problem of acidosis, but at first with small success in unifying our knowledge of that complex subject. Successively it has been shown that in acidosis there may be a production of B-oxybutyric acid or some other specific defect of metabolism, an increase of the urinary ammonia, a diminution of the total carbonic acid of the blood, and of the blood's bicarbonate, an increase of its concentration in hydrogen ions, a diminution in the concentration of carbon dioxide in the alveolar air and of the free carbonic acid in the blood, an impairment of the affinity of the red corpuscles for oxygen, and a depletion of the alkali reserves of the body. Not all of these changes, however, are invariably present, and much confusion has resulted from the attempt to distinguish essential or primary phenomena.

At length it has become clear that acidosis is, from the standpoint of physical science, no simple and unitary state or process, but that, like metabolism or respiration, its unity is biological or functional, and that it consists in any disturbance, large enough and so long enduring as to be properly called pathological, of the regulation of alkalinity in the body. What are the disturbances to which this regulatory process is liable? They are such as are made possible by its normal and essential 1 The Samuel D. Gross lecture, 1916.

peculiarities and general characteristics. These peculiarities can only be the object of special physiological investigations and the subject of special physiological knowledge. But in great part the more general characteristics are those of all organic regulations, and at this very point organic regulation is to-day best understood and analyzed. Accordingly, the description of acidosis must rest upon a clear definition of the nature of organization itself; it may then, in turn, help to define the larger problem.

This conclusion points straight back to Aristotle, whose great attainments as a zoologist together with his extreme virtuosity in conceiving and applying abstract ideas and formulas led him to an analysis of organization that remained the best for more than two thousand years. The words of Aristotle are as follows:

The animal organism must be conceived after the similitude of a well-governed commonwealth. When order is once established in it there is no more need of a separate monarch to preside over each several task. The individuals each play their assigned part as it is ordered, and one thing follows another in its accustomed order. So in animals there is the same orderliness-nature taking the place of custom-and each part naturally doing his own work as nature has composed them. There is no need then of a soul in each part, but she resides in a kind of central governing place of the body, and the remaining parts live by continuity of natural structure, and play the parts Nature would have them play. ["De motu animalium,' II., 7034, 30-35, Oxford, 1912.]

This statement surpasses the efforts of the modern philosophers, who either have not understood the problem at all, or, like Leibnitz and Kant, have but imperfectly conceived it. The earlier modern biologists are also inferior to Aristotle, for when they have perceived the riddle of organization, it has led them into sterile vitalistic theories or mere bewilderment. But during the last century there took place a steady improvement in the biological analysis and

lately the subject has been partly cleared of misunderstanding, so that it is to-day in the minds of most thoughtful investigators. In the nineteenth century the concept of organization appears for the first time as an explicit postulate of scientific research. Of course there has never been a period when the idea of function was absent from physiological investigation. And it would be an almost hopeless task to trace the transformation of this idea, with widening experience, into the larger one of organization. Provisionally it may therefore suffice to note the conscious and deliberate use of the latter idea in Cuvier's so-called law. According to this hypothesis it is possible after a careful study of any one part of an animal, for example a tooth, to reconstruct the whole. Nothing could correspond more perfectly with Aristotle's original position concerning the organic relation between the parts and the whole.

Physiology was more deliberate in setting up the principle, because organic activity is harder to define and to describe. At least as early as the time of Johannes Müller the idea was clearly grasped. But not until the establishment of experimental morphology did it become overtly a guiding principle of physiological research. One very important influence toward this result is to be found in the speculations of von Baer.

The truly Aristotelian idea of internal teleology of the organism is at the bottom of von Baer's biological philosophy. Bichat and he are the first of the organicists. Their successor is Claude Bernard. This great man, whose purely mechanistic researches stand at the foundation of many departments of physiology, steadily exerted all his influence in favor of the idea of organization. He recognized a directive and organizing idea in the animal, and again and again insisted upon it. Yet his analysis of the problem, like that of von Baer, was not

complete. Though he, like all other physiologists, employed the idea of functional activity as a guide in research, though he was fully aware of Cuvier's method in paleontology, his just concern for the integrity of physiological method beguiled him into declaring that "the metaphysical evolutive force by which we may characterize life is useless in science, because, existing apart from physical forces, it can exercise no influence upon them."

This, strange to say, is an old error of Kant's. It is as if one should declare that the idea of the periodic system of the elements is useless to science, because, existing apart from the physical forces, it can exereise no influence upon them. What Claude Bernard well knew, but failed here to point out, is that organization, like the second law of thermodynamics, is a condition of those physio-chemical phenomena which were the subject of his investigations. At times, however, he stated the case more correctly.

During the later years of von Baer and Claude Bernard, the ideas of Darwin were accomplishing a revolution in general biology. Not the least important result was at least temporarily to establish adaptations as the most positive of realities. Yet an adaptation is only to be defined in terms of organization. In the orthodox Darwinian view it is that which contributes to the preservation of the whole. There is nothing in its merely physical character which enables us to recognize it as an adaptation. Only its function reveals its true nature.

In the course of time some of Darwin's original positions have been weakened and the more extreme views of his followers overthrown. As a result this manner of thinking about adaptation is somewhat out of fashion. But it endured quite long enough to leave its mark upon several departments of the science. And it is very doubtful if any one will be bold enough

ever again to put aside the idea of function itself or to deny its necessary implications.

Meanwhile a number of independent lines of investigation have arisen from Darwin's researches. One of the most interesting of these is the study of experimental morphology to which Sachs gave an impetus. This subject appears to have developed, partly at least, as the realization of a program of research founded upon Roux's quasi-philosophical analysis of the characteristics of life.

Such a process is a genuine curiosity in the history of science. According to Roux the living being may be defined as a natural object which possesses nine characteristic autonomous activities, e. g., autonomous excretion, autonomous ingestion, autonomous multiplication, autonomous transmission of hereditary characteristics, etc. This conception, as Roux admits, is closely related to Herbert Spencer's famous conception of life as "the continuous adjustment of internal relations to external relations." Roux's discussion of the subject was independent of Spencer's influence and, in its specification of conditions, his analysis possesses certain advantages over the English philosopher's more abstract statement. But, from the standpoint of physical science, it is gravely deficient in method and has never been regarded as more than a preliminary statement of the several physiological aspects of the fact of organization.

What has given Roux's investigation a certain value and influence is that there is thus presented, however dogmatically, a provisional discrimination of organic activities as a basis for the experimental physiological study of organization itself. With the foundation of experimental morphology the problem of organization assumes its proper place in physiological research. The experimental results of the new science clearly prove that the place is

secure.