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stimulating effect of chocolate was attributed to the high fat content of this beverage. Very ripe fruit increased the catalase of the blood quickly and extensively, while less ripe fruit did not. This was attributed to the fact that the very ripe fruit contained much sugar, which was quickly absorbed, taken to the liver, and stimulated this organ to an increased output of catalase, whereas the less ripe fruit contained less sugar and hence did not stimulate the liver so strongly. The meat digest increased the catalase of the blood very quickly and extensively, whereas meat, eaten as such, did not act so quickly, due presumably to the time taken for digestion. The meat extract and beef juice produced a small increase in catalase.

Dogs were used in studying the effect of moderate exercise on catalase. The animal was placed in a treadwheel and by a little coaxing was induced to run and thus turn the the wheel at a rate of about five miles per hour. The catalase in 0.5 c.c. of blood taken from the external jugular was determined before the exercise as well as at 15-minute intervals during the exercise. It was found that the effect of moderate exercise was to increase the catalase of the blood from 15 to 20 per cent. in most of the dogs used.

Domestic rabbits were used in studying the effect of strenous exercise and fatigue on catalase. The rabbits were also placed in the wheel, which was turned slowly by hand so that the direction in which the wheel was rotated could be changed to suit the direction in which the rabbit took a notion to run. A few slow turns of the wheel was sufficient to tire and fatigue the rabbit. Every precaution was taken not to abuse or injure the animal in any way. It was found that the strenuous exercise and fatigue decreased the catalase of the blood in some cases by as much as 30 per cent. and that during rest for an hour, the catalase returned to the normal amount and in fact above normal in several instances.

We had already shown that the output of catalase from the liver was increased by stimulating electrically the nerves (splanchnics) distributed to the liver. The explanation that

suggested itself for the increase in catalase during moderate exercise was the stimulation of the liver over the splanchnics to an increased output of this enzyme, while the decrease in catalase during violent exercise and fatigue was due to the using up of catalase in the oxidative processes of the muscles more rapidly than it was being replenished by the liver. The increase in catalase during the periods of rest after hard exercise was attributed to the fact that the liver was putting out catalase in the blood more rapidly that it was being used up in the muscles.

According to the chemical theory as set forth by Ranke, fatigue is due to the accumulation of substances, acid in nature, such as lactic acid, which inhibits or depresses the power of the muscles to contract. It is recognized that the accumulation of these acid substances is due to incomplete or defective oxidation. The decrease in catalase observed in the experiments reported in this paper is offered as the cause for the defective oxidation during hard muscular work and fatigue while the helpful effect of moderate exercise is attributed, in part at least, to the increase in catalase produced in this type of exercise.

From the experiments reported in this paper, the conclusion is drawn that food and exercise produce an increase in catalase with resulting increase in oxidation by stimulating the liver to an increased output of this enzyme. W. E. BURGE PHYSIOLOGICAL LABORATORY OF THE UNIVERSITY OF ILLINOIS

Ranke, "Tetanus," Leipzig, 1865.

SCIENCE

A Weekly Journal devoted to the Advancement of Science, publishing the official notices and proceedings of the American Association for the Advancement of Science Published every Friday by

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Scientific Notes and News

University and Educational News

MICH.

Discussion and Correspondence :Pseudo-psychology: DR. CHRISTIAN A. RUCKThe Position and Prospects of Botany: DR. W. L. CROZIER. Leaf Burn of the Potato and its Relation to the Potato Leafhopper: E. D. BALL. "Fats and Fatty Degeneration:" DR. MARTIN H. FISCHER......

Quotations:

A Medical Entente with America

177

Scientific Books:

Emmons's Principles of Economic Geology: PROFESSOR ALFRED C. LANE. Stokes's Aquatic Microscopy: PROFESSOR M. F. GUYER

179

Special Articles :—

Adaptation in the Photosensitivity of Ciona intestinalis: SELIG HECHT. A Method for preparing Pectin: CHAS. H. HUNT......

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MSS. intended for publication and books, etc., intended for review should be sent to The Editor of Science, Garrison-onHudson, N. Y.

AMERICAN BOTANY AND THE GREAT

WAR

THAT botany, the traditional scientia amabilis, should have a place in the present world war seems almost a contradiction in terms. Yet so far are we from the days when war was the concern of professional soldiers only, that one of the earliest announced requests of the British war commission was for regiments of foresters, who are first of all botanists, for service in the forests of France.

That the activities of all professional botanists should, moreover, be profoundly influenced by the war was inevitable. Botany like other sciences is international. Before the war Germany held a prominent and unique place in the botanical world. A number of American students of botany were trained in her laboratories, and although within the last decade the emigration of American students to Germany had slackened, it was the war which effectually stopped the current.

Germany held moreover an almost complete monopoly of the publication of abstracts of botanical papers. Botanists had come to take it as a matter of course that botanical abstracts would appear in German publications, and two at least of these abstract journals had attained world-wide circulation and prestige. These abstract journals are, of course, no longer available in America, if indeed they are being published. It is natural that in this particular field, now left vacant, American botanists should begin to extend their activities and it is gratifying to note that, at their last annual meeting (January, 1918), the members of the various American botanical societies inaugurated the publication of such a journal under editorship which guarantees its

success.

In incidental, and somewhat unexpected, ways the war has influenced botanical studies. The shortage of potash has stimulated the

study of kelps, and the culture of these and other marine alge; while the increased consumption and rising price of coal has led to the reopening of at least one abandoned mine which has yielded fossil plants of great scientific interest in the past and will be closely watched by paleobotanists this summer. The recently recognized value of certain species of sphagnum moss (especially Sphagnum papillosum and S. palustre) as a substitute for absorbent cotton for use in surgical dressings has enabled the very few botanists who are familiar with this rather difficult genus to render important service to the Red Cross by exploring the sphagnum resources of the country and by advising local Red Cross chapters in their efforts to locate new sources of supply.

Undoubtedly the most striking effect of the great war on American botanists has been to direct their attention more generally than ever before to problems of plant pathology. The food situation, accompanied by the educational campaign of the Food Administration and Department of Agriculture, directed popular attention to the basic fact that humanity is, in the last analysis, directly dependent on green plants for food. Statements that we 66 must save wheat for our allies" lent new interest to the fact that stinking smut of wheat annually costs the United States twenty-two million bushels. Urgent advice that we must use perishable fruits and vegetables to save more concentrated foods for the armies in France called public attention sharply to the fact that fresh fruits and vegetables can not easily be shipped great distances, that they are in truth highly perishable; and finally to the tragic fact that large amounts are annually lost in transit and on the market.

With this increased popular interest went a renewed realization on the part of botanists themselves of the fundamental importance of their work and of their own responsibility in such matters. They knew that stinking smut was preventable and the means of its prevention. They realized the immediate necessity, military necessity even, that it be prevented. With state and federal agencies calling attention to the need for increased utilization of fruits and vegetables came the realization that

five to ten per cent. of our eighty million dollar apple crop is destroyed by diseases the control of which is well understood and aroused the determination that they should in fact be controlled.

The case of losses which occur on the market was not so simple. The methods of control of plant diseases which cause losses of fruits and vegetables in transit have been worked out in a few instances, whereas about others very little is known. The obligation, however, was equally apparent, so far as methods of control were known they must be applied, where none were known they must be found.

With such a task before them it is not surprising that American botanists have organized as never before and as a result this summer is seeing a campaign for the control of plant diseases never approached in this country. With this there is being carried on an increased amount of research on fundamental scientific questions of significance in the control of plant disease.

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This increased usefulness is being brought about by better organization of the men already engaged in the work and by much outside assistance from botanists who are not, professionally, plant pathologists. Both these changes would, indeed, have been necessary in order to keep up even the normal activities in plant pathology, for the number of workers in this line, as in all lines, has been reduced by the needs of the army and navy. The younger men and in particular the graduate students preparing for work in plant pathology have enlisted in large numbers.

The organization of American botanists for greater service in the study and control of plant diseases is under the immediate direction of the War Board of American Pathologists, a representative committee appointed by the American Phytopathological Society, at its annual meeting, January, 1918. The work which this committee has already accomplished is too varied to be detailed. Three phases of its activity will sufficiently illustrate the scope and methods of its work. These are the man power census, the extension work, and the assistance of research.

A reorganization of man power, if much was

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to be accomplished, was rendered absolutely necessary by the inroads due to enlistment for military service. The first step in this direction was taken by the man power census. A brief questionnaire was sent to every botanist in America, who could be reached, and on this card each man was requested to indicate his training, degree of availability and willingness to take up emergency work in plant pathology. The replies have been most gratifying in number and tone. Teachers of botany and investigators in other fields have in considerable numbers indicated a willingness to lay aside temporarily their own investigations, investigations usually of great importance to the progress of botanical science, and take up work on the control of plant diseases.

The aim of the extension work of the committee is to make available everywhere in America information now available anywhere in America. Pathologists in various states were asked to contribute any information they might have, published or unpublished, which might be of service in other sections. Responses to this request also have been prompt and enthusiastic. Pathologists all over the country have placed in the hands of the committee for general distribution information which they have acquired in their own work and which seemed likely to be useful to other workers. They have done this frequently without waiting to insure credit to themselves by prior publication. Instead of safety first they have placed service first.

In research the effort has been to call attention to those problems which were of most pressing importance and to coordinate the work of investigators in different regions. Much has been accomplished here in so arranging work that the efforts of one investigator should supplement rather than duplicate those of his neighbor.

The results of these lines of effort can not fail to be of great service. Undoubtedly the greatest immediate gain will come from the extension work, from the distribution of information to the plant pathologists of every state in the union and the further distribution of this information through the county agents and the farm demonstrators to the actual pro

ducers. It is highly probable, however, that the greatest ultimate good to plant pathology as a science and to the nation will come from the temporary enlistment of a large number of botanists from other lines. This increase is not a gain in numbers merely but a gain in different technical training, different methods of work, new points of view. So close are the interrelations of the natural sciences that striking contributions to a science are frequently made by a newcomer in the field who has been well trained in another not too closely related field. Thus it is only natural to expect that from the present mobilization of botanists of all kinds in plant pathology will come striking and valuable contributions to that science.

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Do you include any not listed above? ...... 9. Which of the following do you include? (Cross out any not included.) Dalton's atomic theory, law of constant proportions, combining weights, valence, Boyle's law, kinetic molecular hypothesis, Avogardo's law, Gay-Lussac's law, catalytic agent, allotropism, osmotic pressure, freezing and boiling point effects, gram molecular volume law, DuLong and Petit's law, periodic arrangement of elements, Mosely numbers, electron theory, structure of atom, ionization, Faraday's law, equilibrium, thermal equation, colloids.

Mention laws or theories taught and not included in above list

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