beget. Again nature, to secure the proper development of the individual, puts the exercise of the function beyond the reach of whim and rationalizing. It is made instinctive. As we advance it too comes under the domination of overwhelming appetite and passion.

To get and to beget, assimilation and reproduction, are undoubtedly the basic animal functions. Around them are grouped or from them have developed all other activities which from this point of view may be looked upon as subsidiary, accessory and subordinate even though in occasional instances they may appear to be far-removed and exotic. We, as individual animals, are here to maintain the permanence of the species; yet to ensure the fulfilment of this duty we must also maintain our individual selves during our own transitory existence. It is probable, though indeed debatable, that at bottom from the standpoint of the Grand Purpose nothing else matters. If the species die out then to the Universal Plan all else is chaff and dross, even though these be the grandest manifestations of the spirit- the self-abnegation of maternal love, the submergence of the ego in philanthropic endeavor, the creation of a symphonie pathétique, the chiseling of an Apollo Belvedere, the limning of a Sistine Madonna, the erection of a system of religion that is the solace and refuge of a billion souls.

Reduced thus to elementary terms, the phrase "to get and beget" implies a modus operandi that is simplicity itself. But in the animal kingdom at large its practical working out becomes a matter of enormous complexity. Species soon become something much more elaborate than successions of individuals equipped only with digestive and reproductive structures. There come into being animals that people the sea and the air as well as the land; animals that inhabit the desert as well as the swamp; animals that subsist on plants alone or on flesh alone To obtain food animals must be capable of locomotion, wherefore organs of self-propulsion arise; and as a result animals acquire a new function, that of movement. Movement requires muscles and muscles demand a sturdy supporting framework, the bony skeleton. The metabolism of oxygen is also absolutely necessary to the life of animal tissues, and to subserve this purpose the creatures that must remain alive if they are to get and beget take upon themselves the function of respiration. Increasing amounts of food are needed for subsistence, and more and more complicated kinds of food. Thus there occur more and more residue and waste after digestion with the consequence that methods to get rid of the waste must be developed; therefore, we begin to meet with separate and definite organs of elimination. We now find animals that are capable of performing a variety of acts, all of them purposeful in that they assist in keeping the individual adapted to its environment so that it may obtain food to live and that it may live to reproduce its kind. Animals fly

and swim and run; they breathe the air of the atmosphere and the air of the water; they take food into stomachs that have structures that are especially adapted to the preparation of special types of food for digestion. Meanwhile the continued multiplication and development of function and structure, which are always keeping pace with each other, make necessary a regulating and coordinating apparatus, whereupon there arises the nervous system with its manifold fingers proceeding from and going to a central organ that "registers" sensation and impels to movement. So, too, with the growth of the body and the setting apart of specialized organs there comes the need for some mechanism that distributes nutritive particles to and removes discarded substances from the various parts of the body, when a circulatory system comes into being. Thus we find in time that the animal body in order to perform its relatively few and simple ultimate purposes becomes a wonderful and delicately adjusted aggregation of parts-organs-each of which has its own special function to serve. The individual lives to work out nature's purpose; its organs enact their own proper rôles to assist the individual in the performance of its duties.

But the organs are not the ultimate structural elements of the animal body. They are made up of tissues. Basically again there are only a few types of tissues. There is epithelium, a tissue that covers the surfaces, cavities and organs of the body and lines its numerous ducts. By a process of adaptation for specific purposes epithelium in the evolutionary development of species may be converted into glandular or secreting tissue. There are in addition nervous tissue, bony tissue and muscular tissue. And distributed everywhere throughout the body and making up the supporting and binding framework of all organs and other more complicated structures is connective tissue. Few as they are in number these several tissues by a diversity of arrangement, a diversity of which the theoretical possibilities as regards varying proportions and combinations are practically illimitable, make up all the numerous structures that enter into the constitution of the animal body.

A blood vessel takes its form from the proper arrangement of connective tissue, muscle and epithelium. A different arrangement of connective tissue, epithelium and muscle, with the addition of blood vessels, cartilage and glands, makes up the lung. A still different arrangement of connective tissue, muscle, epithelium, glands and blood vessels, forms the digestive tract. Thus, while at first glance different organs appear as structures that exhibit no similarity or relationship, at bottom they are built up from the same materials; just as the chaste and quiet Doric and the florid and aspiring Gothic may each be assembled from the same stones and the same mortar.

The tissues again are made up of more primitive anatomic units. These units are

the cells, microscopic structures, which are the groundwork of all tissues. Also of a very few fundamental types, the cells by a diversity of modification and arrangement end in forming a variety of tissues. It is the nature and growth and development of the cells that determine the nature and growth and development of the tissues and organs. If the cells of a tissue suffer injury or death then manifestly the tissue undergoes damage or decay to the extent that its cells are influenced. The integrity of tissues or organs depends absolutely on the integrity of their cells, just as the integrity of the individual's body depends on that of its organs, and the integrity of the species on that of its individuals. In the last analysis, therefore, the matter of the maintenance or perpetuity of species comes down to the necessity for the continued life and reproduction of animal cells.

Cells therefore must be endowed with basic functions that are more or less similar to those of the individual. Most of them in the animal body are fixed and do not require the power of locomotion. But to continue to live they must be nourished with the proper food elements. All living cells accordingly have the function of assimilation, the capacity to take into themselves and work over for their own use nutritive particles. Inasmuch, too, as cells are immortal no more than is their earthly host they are continually wearing out and undergoing decay and death. As a matter of fact, the life of most individual cells is much shorter than that of the individual animal or tissue of which they form a part. To maintain and continue the structures which they make up, the cells of the body are therefore throughout an animal's life reproducing themselves and multiplying in an orderly manner. The vigor and amount of their reproduction in health is always determined by the demands that the growth of the animal or the labor it performs puts upon them.

How familiar all this now sounds! We find that the basic functions of the elementary cells are to get and beget, just as were those of the individual animal. To get and beget are the primal duties of the microcosm, man, in the macrocosm, the universe; and to get and beget becomes the similar "first business" of the microcosm, the cell, in the macrocosm, man. In man the exercise of these functions has become instinctive, and nature has safeguarded them from too complete a control of the will by transferring their practise to the domain of the emotions. In the cells both processes are entirely automatic and have become inherent activities: so far we can determine they consist in blind and native reaction on the part of the cells to proper irritation or stimulus.

as

*

It is anomalous to find the things of nature. endowed and burdened with unnecessary adjuncts. If to get and beget involved no labor, no strain, no effort, it is therefore likely that

the individual would develop few added functions. But it so happens that the business of getting food and of begetting offspring is performed throughout the animal world with toil, with turmoil and with conflict. The quest for food proceeds over long distances. It takes the animal beneath the earth, to the river's brink and to the tree top. It lures him into the trackless jungle and up the rocky declivities of the mountain. As carnivorous appetite develops the earth becomes a scene of prey and carnage; and were animals equipped only to eat and to reproduce there would soon survive only a few species of overpowering build. Indeed with the continual diminution of the food supply that the slaughter of defenseless animals would bring about the individuals of the few surviving species would in time take to devouring one another, and the extermination of animal life would occur.

It will at once be seen that if animals are to continue to exist they must be furnished with adaptive and defensive mechanisms against the elementary forces of nature on the one hand, and hosts of animal enemies on the other. As means of defense there arise fleetness of foot, or claws, or horns, or strength of jaw or of limb. Protective coloration that merges the animal more or less completely with its natural environment and thus renders it difficult of detection becomes another potent method for species preservation. Scores and hundreds of specific defensive appliances come into being, and it is the common thing for them to be of use also in obtaining and handling food. Thus the claws of animals, the trunk of the elephant, or the horn of the rhinoceros can be brought into play either as a weapon of attack or defense, or as an instrument to obtain food.

It comes about that the ability to protect self becomes as important a function or an attribute of the individual as assimilation, reproduction and locomotion. If an animal would live it must defend itself, it must resist, just as surely as it must eat. It must resist heat and cold, and bog and rocks; it must resist other animals even though this resistance may mean merely the ability to move more swiftly. Indeed, the continuance of animal life on this planet is unthinkable unless we conceive resistance to be a basic function and attribute of the individual.

We must remember that resistance is never absolute. The concept always takes account only of relative values. No matter how great may appear the normal development of an animal's resistance to any particular force, we can always imagine an increase or intensification of the force that would break through the individual's defense. For every species of animal there is a certain native capacity of resistance between maximum and minimum limits to the various stresses to which the species may in its ordinary environment be subjected. This resistance is common to all the individuals of the species and may be

called the normal or standard resistance of the species. Because of unusually favorable or unfavorable experiences and environment the native resistance of certain individuals to special stresses may be increased or diminished. Such individuals are then looked upon as being over-resistant or over-susceptible to the particular force under consideration. It happens, therefore, that before we may discuss or speculate concerning increases lowerings of resistance to special external factors we must have some idea of what is the ordinary and normal defensive capacity of the species. And our information will be all the more exact if in addition we can gain some data as to how close an approximation to the normal is exhibited by individuals that may be under observation under the ordinary conditions of existence.

or

Our knowledge of the development of instruments and methods of protection or adaptation is as yet by no means further than the hypothetical stage. Lamarckianism would assign their origin to the response or reaction of definite tissues to external forces,-stimuli, irritations; and would make their full development follow upon the cumulative transmission by inheritance of acquired traits plus further growth from continued use by the individual. Neo-Darwinianism takes a different view. It would begin by denying the transmission by inheritance of characteristics for instance, an unusually highly developed muscle, a mutilation, an overgrowth of tissue into a structure resembling a horn-which the individual acquired during its lifetime. The individual may develop inherited characteristics to an unusual degree or it may suffer decay in any of its parts; but it can transmit to offspring no specific trait or bodily characteristic that it has not itself inherited. Now among the myriads of individuals of the same species there is potentially a tremendous capacity of variation by inheritance of bodily characteristics. Unusually large parents may breed larger and smaller offspring, while unusually small ones may beget smaller and larger individuals. Nevertheless, it so works out that more large offspring originate from large parents, and vice versa. Therefore, if it so happens that large individuals are better adapted to their natural environment than small ones, the former will in the long run after many generations increase and survive, while the latter will diminish and die out. Lamarckianism would have it that special characteristics are developed by means and as a result of adaptation to environment. NeoDarwinianism would maintain that an adaptation to environment is the result of the possession of certain necessary characteristics that were inherited by the individual and that those that lack the physical capacity of adaptation in time die out, while the adapted ones survive until at last only the adaptable individuals are left. Neo-Darwinianism does not deny that inherited characteristics are

capable of varied degrees of development. Every animal is born with tissues that have their maximum and minimum possibilities. It is probably true that their full capabilities are never exercised and developed; if for no other reason, than for the simple one that too much attention to the development of one characteristic at once implies neglect of others with the consequent decay of the latter with final injury to the body as a whole.

It would be tremendously important could we know the truth concerning the natural origin and further development of fundamental biological attributes like defensive or adaptive mechanisms, all of which can be looked upon as coming within the province of the concept, resistance. We cannot affirm the truth, yet the cases teach us anew how strictly to our purpose in medicine is any basic biological generalization. In medicine, in considering the problem of disease from the broadest possible standpoint, that is, from the point of view of the nature of disease and its effects, we use no term more than this one, resistance. It is continually and forever on our tongues, oftentimes without there being behind it any concrete idea that gave it utterance. Hard to define, perhaps impossible of definition, resistance to disease is nevertheless a very real phenomenon. Even the child and the savage have some idea of it. Both are struck by its manifestations. Yet not infrequently the cultivated and the professionals have ideas which, though based on vastly more numerous and more exact observations, are little more satisfying than those of the child and the savage. This circumstance would at once indicate that resistance to disease, though a very real and striking attribute of animal life, is nevertheless at the very least a mighty complex made up perhaps of many simples that are continually crossing and re-crossing one another, with the consequent production of paradoxes that such a situation gives birth to. For a long time it has appeared to the author that an adequate presentation of the subject of resistance, one that would take into account and would strive to give a proper interpretation to all the conflicting data that apparently come under the purview of resistance to disease, is to-day beyond the powers of any man. He therefore has no overweening ambition to attempt the task. But he does desire to treat of a few manifestations of what would appear to enter into resistance to infections in general and to tuberculous infection in particular, from the biological point of view, more or less along the lines that have been laid down in the foregoing pages. He adopts this point of attack because he considers it the most fundamental method of approach.

(Some Phases of Resistance to be continued in the July number under the title, "The Reaction of Tissues to Irritation.")

"Fact gathering is the A B C of surveys," says Shelby M. Harrison, director of the Department of Surveys and Exhibits of the Russell Sage Foundation, in a recent pamphlet entitled "Community Action Through Surveys," and then continues: "The survey is an attempt in the field of civic and social reform to do what the civil engineer does before he starts to lay out a railroad, what the sanitarian does before he starts a campaign against malaria, what the scientific physician does before he treats a case, what the careful financier does before he develops a mining property, what the modern manufacturer does before he locates a new manufacturing plant. It is, in short, an attempt to substitute tested information for conjecture or mere belief."

"But who is to gather the facts, and who is to make the survey, especially in the small community?" says the incredulous business man, the physician or the social worker, who is confronted with the appeal for a stocktaking of his community. There are a number of possibilities here, but we may narrow them down to four.

Who is to Make Survey?

Bearing in mind that we are considering primarily the small town and country district, such as the county or a group of villages or a city of less than 30,000 population, where the social resources of the community are naturally limited, and where all too frequently the vision of such socially minded people as are in the community is apt to be dwarfed, who is to do the survey?

Shall it be an insider or an outsider? This is a primary consideration. Generally speaking, the insider here has the advantage of knowing the community, but, particularly in a small city or county, for example, this very intimate knowledge would blind an insider to a true perspective of the entire situation. Then again, the insider always has friends, and enemies, too, who must be conciliated or pleased, and no matter how courageous he may be, these very personalities will, to a certain extent, limit his observation and mar his vision. While the outsider is handicapped by a lack of knowledge, he or she usually comes in more or less as

Reprinted by permission with certain modifications from "The Trained Nurse and Hospital Review" for January and February, 1917. Reprints of this article will be furnished free on request to the National Tuberculosis Association, 381 Fourth Ave., New York.

an expert with some previous knowledge of what a survey is to be, and possibly with some previous experience. The outsider also lacks a personal connection and can approach the problem from an entirely unbiased point of view. By an outsider, I mean not only the person who is imported particularly to make a survey, but a nurse, for example, who is brought in and has been working in the community for a time, but who is really not a native of the community. The outsider, therefore, seems to have a distinct advantage in surveying the small community.

Nurse or Social Worker?

Another consideration. Shall the surveyor be a nurse or a social worker, or possibly the happy combination of both? Since the survey which we are considering here is limited to an inventory of the health conditions of the community, a nurse would seem to have a real advantage over the ordinary social worker. The nurse has the medical training. She has had to some extent, at least, some experience in public health work. She appreciates the preventive side of the problem. She knows how to approach physicians, and furthermore, her technical skill gives her an entrée into the homes of patients or suspected patients, which no social worker can secure. A social worker does have the advantage of a broad training, which takes in not only the health side of the problem, but its relation to other problems of social betterment. This advantage, however, is more than offset, it seems to me, by the many additional assets which the nurse possesses. The ideal combination would be a nurse who had training as a social worker. There are some of these, but their number is still far from legion.

Personal Characteristics

Taking it for granted, then, that the survey should be made by an outsider, and that it preferably should be done by a nurse with social training, what distinctive personal characteristics should such a nurse possess that would qualify her especially for survey work? From considerable observation of nurses and social workers engaged in the public-health field, I have come to classify them into two groups, according to their temperament and personality, first, the investigator type; and secondly, the promoter type. It is not often

that these two types of personality go together. Most nurses fall into one or the other of these categories, that is, they are either inherently investigators, the diggers of facts, the keen observers, the collectors of statistics, or they are the organizers, the promoters, the publicity agents-the workers who can arouse enthusiasm and crystalize it into some form of definite organization.

Any nurse who attempts to make a survey should first of all ask herself, "Do I fall in the first category, or do I temperamentally fit in the second?" If the latter, she should immediately recognize her own limitations and not attempt to do survey work unless her ability as a promoter is complemented by that of a nurse of the other type. As to her education, character, tact, energy, ingenuity, much may be said. These are prime requisites for a surveyor. She cannot hope to succeed unless she has a love for the work which amounts almost to a passion. Any kind of survey work is hard and discouraging, and whoever undertakes it must have more than ordinary zeal. That she must be familiar in a general way with the problems which she has to confront, goes without saying, but how often do we find that nurses attempt to make surveys with no idea whatever as to what their study should comprehend.

What Facts are Desired

What are the facts which a survey nurse who attempts to make a study of tuberculosis in a small community should look for? Within the limits of an article of this character, one cannot go into much detail, but generally speaking, a survey should take into account not only the extent of the disease in terms of deaths and number of cases; not only the existing measures for the control of the disease, both private and public, but should also, to some extent, be able to make suggestions and recommendations for an adequate campaign on the basis of the facts studied. More than this, a real survey will make intelligible to the people of the community, through an exhibit or otherwise, a true picture of the city, town or county, as the surveyor sees it. In a word, the task which confronts the nurse is not only to collect the facts, but to make them available for community action.

What has been said so far has been more or less general, but I propose in the rest of this article to give some practical suggestions on how to do it. These suggestions will in a measure open the door for further inquiry, and will lead to sources that will give more complete information.

Mortality Statistics

First of all, then, as to mortality statistics. How are we going to get reliable figures? One would suppose that in an average community where vital statistics have been recorded for a number of years, the

mortality statistics with regard to a disease like tuberculosis would at least be reliable. Experience has proven, however, that there is hardly a community, and especially the small communities in this country, where the mortality statistics with regard to tuberculosis can be depended upon, as they are recorded in the annual reports published by boards of health. The only way in which a survey nurse can get reliable mortality statistics with regard to tuberculosis is to take the actual death certificates for the period of years under observation, preferably five, ten or fifteen years according as the certificates are available, and analyze them herself, making an entirely new tabulation from beginning to end. The United States Bureau of the Census publishes a volume entitled "Index of Joint Causes of Death," which may be obtained free of charge on application. This volume will show the amateur registrar some of the pit-falls into which the average board of health readily stumbles, when it compiles its mortality statistics on tuberculosis. There are over 200 possible designations by which tuberculosis may be reported to the Board of Health, such as, for example, congestion of the lungs, pulmonary hemorrhage, hip disease, chronic bronchitis, etc. It is obvious that once a local registrar of vital statistics has accepted a faulty death certificate from a physician, where the cause of death is improperly indicated, no one can say with authority what was the real cause of death, unless he goes back to the physician. This is usually a practical impossibility.* The United States Bureau of the Census, therefore, uses its discretion in classifying such improper causes, and frequently, when the local registrar would classify them in one way, the Census Bureau classified them otherwise. There is a uniform classification by the Bureau of the Census, and if reliable statistics can be obtained from that body for a period of ten or fifteen years, much analysis of the statistics locally will be avoided. The difficulty, however, is that the Bureau of the Census cannot give complete analyses of statistics for sex, age, conjugal condition, occupation, etc., which are extremely vital.

As to the type of information which one should expect to get from an analysis of vital statistics, Miss Lilian D. Brandt's little pamphlet entitled "Facts About Tuberculosis," is as helpful as anything that could be suggested for nurses. Miss Brandt points out the kind of facts that one should look for, and indicates how they may be presented in the most helpful manner. There will, of course, be many additional local facts that will count in an analysis of the death rate, which the surveyor must consider. When a complete and extensive analysis of the local mortal

* See paper on "Misleading Mortality Statistics." by the author, in Transactions of National Tuberculosis Association, 1912.

"Facts about Tuberculosis," Lilian D. Brandt, Journal of the Outdoor Life Publishing Company, 381 Fourth Avenue. Price, 25c.