between cancer cells and normal body cells and to determine if there be substances which may affect the one and not the other, the object being, of course, to obtain such a substance for therapeutic purposes. Efforts are also being constantly made to discover by experimental methods, the cause of malignant diseases.

Department of Biology, in charge of Mr. M. C. Marsh.

The work for the year has been a consistent continuation of mouse breeding, the experimental investigations which have been in progress since 1914, together with work recently started and taking a new direction. The accumulated data concerning experiments with acarine parasites of mice in relation to the origin of tumors, and concerning trauma experiments, were gathered together in a short paper which was read at the tenth annual meeting of the American Association for Cancer Research in April, 1917, at New York. A more complete account was published during the year in Vol. II, No. 3 of the Journal of Cancer Research.

The attempts to produce tumors by various forms of trauma and to throw additional light on the association of trauma with the genesis of tumors have been continued. The use of acarines has been abandoned in these experiments which lately have been concerned chiefly with the simple injection, in various ways, of ordinary air. The results at present indicate that such air injections act as a form of trauma, and share with other forms of injury a slight tendency to favor tumor growth, and thus to participate to some extent as a causative factor in the origin of tumors. The inquiry seems worth some further continuation as an exhibition of the role of trauma but it does not appear that the air itself acts in any other way as an excitant to proliferation of the mammary glands of mice.

Special interest attaches to the stock of mice produced by inbreeding of cancer mice from a single pair of parents in which a high hereditary tendency to produce mammary tumors existed. The mouse breeding is now almost entirely inbreeding, and consists mainly of two strains of mice, one giving a low cancer rate and the other an unusually high rate. Owing to the use of large numbers of mire in experimental work, the sending of several

hundred to the Hygienic Laboratory in Washington and the elimination of some unnecessary stock, the total number of mice has become much depleted and numbers not much over one thousand at the end of the year. A gradual and considerable increase will occur during 1918.

The strain of lower tumor rate produces about 20 per cent of tumors during the lifetime of the female mice. From the other one can realize 65 per cent of tumor mice among all female breeders surviving beyond six months of age. Nearly all the tumors are produced between the sixth and twelfth months of age and not 5 per cent of breeders become one year old without developing tumors. This strain may reasonably be considered to carry a tendency to produce spontaneous tumors of the mammary gland in 95-100 per cent of all female breeders. In non-breeders the development of tumors is much delayed and the total incidence is probably reduced. The strain, though not especially vigorous nor prolific, continues to breed freely and has reached the seventh inbred generation. The fourth generation is producing the expected high proportion of tumor mice while the fifth is just arriving at cancer age. From this strain and other sources the stock of mice has furnished the Laboratory, chiefly during the last half of 1917, about 170 spontaneous tumor mice for experimental work of various kinds and continues to produce a current supply of tumor material.

It is plain that this strain of mice, in which nearly all the females not dying early, develop tumors, affords excellent material for attempts to retard or prevent the development of such growths. Feeding experiments are about to begin in which the nutrition will be varied within the limits permissible, at first by means of a low protein diet and appropriate single staple foods such as grains. These are being preceded by controls in normal feeding. Each attempt of this sort to gain information concerning the conditions which may prevent cancer must obviously extend over a long period. These attempts must be begun, at present at least, with the youngest mice at or soon after weaning. With the non-breeders about one year must elapse before inferences may begin to be drawn and more definite conclusions may require several months more. With breeding mice the time periods may

be somewhat shortened. In either case it is advisable to have as many experiments simultaneously in progress as resources permit.

Department of Biological Chemistry, in charge of Dr. G. H. A. Clowes.

The work of this department may be divided, as in previous reports into two main parts; routine, and research work. The routine consists, for the most part, of serum tests which are carried out on all cases presenting themselves for treatment in the hospital and dispensary and from outside sources. The data accumulated in this manner have frequently proved of value not only in aiding clinicians in the diagnosis of cancer, syphilis, tuberculosis, etc., but also, the tests being conducted on a quantitative basis, may be repeated from time to time and thus afford a valuable index of the results obtained in the various treatments. A survey of upwards of ten thousand cases on which tests have been made in the course of the last eight years shows hundreds of cases in which the information obtained in the laboratory confirmed otherwise doubtful diagnoses and a considerable number of cases in which an incorrect diagnosis was reversed as a result of laboratory findings.

In a previous report attention has been drawn to the fact that the transplanted rat and mouse tumors, which for lack of better material have been utilized for extensive investigations regarding immunity, etc., in this and other laboratories, are not in any sense comparable to human cancer. The blood reactions exhibited by these animals differ materially from those exhibited by human cases and it was considered very improbable that the curative results obtained by using chemicals, sera, etc., on animals with transplanted tumors afforded any criterion regarding the results which might be attained were primary animal tumors available.

Fortunately the success which has attended Mr. Marsh's attempts to develop a strain of mice exhibiting a high percentage of primary tumors has made it possible for him to put a considerable number of primary tumor mice at the disposal of the chemical laboratory and it is interesting to note that such mice exhibit blood reactions comparable with those exhibited by human cancer cases at similarly advanced stages of development. While

it is still too early to report the effects exerted by chemicals on such tumors, preliminary experiments indicate considerable differences from those previously reported on transplated tumors. These primary mouse tumors have already afforded means of testing the influence exerted on tumors by chmicals which it is desired to use in amounts not far removed from the fatal dose which, for obvious reasons, cannot be tried out on human beings. In two previous reports from this Laboratory, attention has been drawn to the marked differences in chemical composition exhibited by rapidly proliferating tumors as compared with slowgrowing or stationary tumors, particularly as regards the proportions of certain commonly occurring salts like those of sodium, potassium and calcium. The effects exerted by the salts in question on living cell protoplasm were shown to closely parallel the effects exerted by the same salts or salt combinations on such purely physical systems as soap films, emulsions of oil and water, and colloidal suspensions and the theory was advanced that while certain salts render the outer film of protoplasm more permeable to water by promoting the dispersion of its constituents in water, others render the films in question less permeable and that consequently the intake and utilization of food stuffs and indirectly the proliferation of cells must depend upon the ratio in which the salts in question are mobilized in the vicinity of the protoplasmic membrane.

In the course of the last year additional experimental data have been accumulated in this direction and it has been found possible to parallel the results obtained on living cells in experiments on jellies, blood clots, etc., and since cell protoplasm appears under certain conditions to possess a physical constitution approximating to that of a jelly and the plasma of blood appears to present a striking resemblance to cell plasma, both psysically and chemically, it is to be hoped that further investigations along these lines may throw more light on the physical constitution and the mode of nutrition of cancer cells and indicate some means of limiting their development. Several preliminary communications on this subject have been published from this laboratory in the course of this year and more extensive papers are now in the course of preparation.

Hospital Department, in charge of Dr. B. F. Schreiner.

The following is a resumé of the work done at the State Institute in the dispensary and hospital for the year ending December, 1917. During this period there were seen in the dispensary, 173 cases of which 129 were admitted for treatment. Forty-four (44) cases were seen for diagnosis and were referred back to their physicians for treatment. During the year there were 108 patients in the hospital for treatment. The number of days spent in the hospital by a patient ranges from 2 to 319. In all there were 79 operations performed both in the dispensary and in the hospital. Of these there were 38 major operations and 41 minor operations. Twenty-two (22) deaths occurred in the Institute during the year, all of which had complete autopsies performed. There were given during the year, 1448 X-ray treatments and 305 radium treatments.

The work of the Institute is divided into three classes. First, the cooperation with physicians in making diagnoses in obscure or doubtful cases. Second, the routine treatment of a limited number of dispensary cases by X-ray and Radium. Thirdly, a research problem. The routine work of admission comprises the following: On admission, a careful history including family history, personal history, and present illness is taken; routine physical examination. All cases are subjected to Wassermann tests. All cases in the hospital have in addition complete blood studies, complete urinalysis, and a large group are now on metabolic studies. It is too early to make any definite report on this work but we hope to be able to report on a group of one hundred cases about April, 1918.

In the following tabulation of cases, we have followed the pathological classification primarily and secondarily, and anatomical classification.