February 24-(U.): Almost normal, save one or two casts. (B.): Hamburg steak; coffee and cream; whole wheat mush dextrosed and cream.

(L.) Hamburg steak; whole wheat mush dextrosed and cream; coffee.

(D.): Pea soup; roast beef; boiled potato; lettuce, plain; graham bread and butter; dates; water.

February 25.-(U.): Almost normal.

(B.): Hamburg steak; coffee and cream; baked potato; whole wheat mush dextrosed and cream; water.

(L.): Same as breakfast.

(D.): Beef soup; boiled lamb and potato and Lima beans; celery; squash; pudding; cream; water.

February 26.—(U.): True and false casts; filaments of catarrh of the size of casts and long. Was the condition caused by the pudding? (B.): Hamburg steak; baked potato; coffee; whole wheat mush dextrosed and cream.

(L.) Hamburg steak; baked potato; butter; bread; pudding; coffee and cream.

(D.): Tomato soup; baked white fish; roast pork; string beans; boiled potato; water; cream; apple pie; chcese.

February 27-(U.): False and true kidney casts; cystin, probably due to the fish; slight bile.

(B.): Hamburg steak; coffee and cream; baked potato; butter. (L.) Hamburg steak; baked potato; coffee; whole wheat mush dextrosed and cream.

(D.): Soup; boiled dinner of corned beef, beets, cabbage, carrot; tea; water; milk.

February 28.-(U.): Slight bile; otherwise normal.

(B.): Hamburg steak; black pepper; coffee; whole wheat mush glucosed and cream.

(L.): Same, save pepper.

Intermediate.-White of egg.

(D.) Clam chowder; roast mutton; onions; boiled potato; milk; water; prune pie and cheese; dates.

March 1-(U.): A few false kidney casts.

[TO BE CONTINUED.]

THE NECESSARY COÖPERATION OF HEREDITY AND BACTERIOLOGY IN THE PRODUCTION OF DISEASE.

BY OWEN C. BROWN, B. A., M. D., DETROIT, MICHIGAN.

THE object of this paper is to show the necessary coöperation of heredity and bacteriology in the production of disease, and that if the former were removed (an assumed possibility only) there would be no manifestation of the latter as a pathogenic factor.

Heredity, hereditary disease, and hereditary transmission are terms *Read before the WAYNE COUNTY (Detroit) MEDICAL SOCIETY.

used to designate the same principle, namely, the transmission from an organism to its offspring of some peculiarity, trait or disease: the first with "likenesses" distinguishes the species; the second and last named are common to the genus. "The laws of heredity as understood in their entirety are that each plant or animal produces others of like kind with itself; this likeness being more a question of general structure than of particular traits." While Mr. Spencer does not pretend to give a positive definition of heredity in his "Biology," he makes an excellent attempt to explain it by means of his mechanic theory, persistency of force and the tendency of all things organic to seek an equilibrium. Heredity is said to be the correlation of variation. Taken in its universal application, it applies with equal force to those processes known as diseases, as to likenesses and traits. A good definition of heredity is desirable.

According to Haeckel, heredity is the memory of the plastidules, variability their power of perception; the former brings about constancy, the latter diversity in organic forms. If heredity is memory and variability the acquisition of new experiences, and since memory enables the organism to recall past events that have occurred within its own life period, heredity might be called the memory of ancestral deviations as regards diseases; or making free use of Haeckel's definition, disease might be called the memory of ancestral sins. This may appear somewhat nonsensical, but it must be remembered that scientists of Professor Haeckel's attainments often pass long periods in the clouds. Our actions are of course governed by our experiences-to a great extent at least. And as experience depends wholly upon memory, to a certain extent it is true that life is memory. Again as the power to reproduce its like is characteristic of all living things, it is conceivable that this power is the memory, by the ovum, of the experiences of its ancestors, and that there exists in the ovum an organization of some kind which enables it to transmit likenesses as well as peculiarities and diseases from generation to generation.

It is also a well-known fact, founded chiefly upon the studies and researches of Charles Darwin, that secondary sexual characteristics of each sex lie dormant or latent in the opposite sex, in a condition to be evolved when necessary or under certain special circumstances. Let us quote from his work on Variation: "In every female all the secondary male characteristics and in every male all the secondary female characteristics exist in a latent state, ready to be evolved under certain conditions. For instance, it is possible for a good milking cow to transmit her good milking qualities through her male offspring to future generations, for we may confidently believe that these qualities are present though latent in the males of each generation. So it is with the game cock, which can transmit his superiority in courage and vigor through the female to his offspring."

It is a well-known fact that diseases peculiar to the male sex can be transmitted through the female to the grandsons. The history of 1 SPENCER, HERBERT: "Biology."

the Plante family which came under my observation some years ago when I was practicing in Eastern Canada, is an illustration of this point. Israel Lemay died of pulmonary consumption which he had inherited from his father. He left a son and daughter, the latter of whom married Plante and six sons and five daughters were born to them. At the date of my leaving that part of the country five daughters had married and apparently were healthy; the elder Plante and his wife, then over eighty years of age, were both healthy; while the six sons had followed each other to the grave, the first dying from consumption in 1875, the last in 1892. One son had moved to another locality, and although one of the first attacked by the disease, was the last to die; the eldest had married and moved to another farm, and he died the last but one. Transmission of the disease through the daughter to the male grandchildren, leaving the female grandchildren and the mother untouched, is worthy of note; for it shows that diseases as well as traits may lie dormant in the system for a generation to be transmitted to the like sex in the descendants. The history of that family. also shows the benefits to be derived from a change of environment in cases of tuberculosis.

Aristotle gives an account of a hen which had ceased laying and assumed the characteristics of the male bird. Other writers have recorded the same fact. Old hens which have ceased laying often acquire a comb, wattles, spurs, the brightly colored plumage and long tail feathers of the cock, assume the habits of the male and even learn to crow. Doubtless the proverb, "crowing hens lay no eggs," has arisen from observation of such facts. Female deer are known to have acquired the horns, hair, odor and sexual desires of the male. These facts and many others to be found in works on natural history, dealing with that complicated subject, heredity, show how traits and peculiarities as well as habits lie dormant in the system and may be evolved by the opposite sex to which they belong; they also show that they may be transmitted through the sex opposite to which they belong to the appropriate sex in the descendants.

We have all doubtless observed that to the age of puberty there is no difference between boys and girls as far as amusements and play are concerned, making due allowance, of course, for the mother's influence. The possession of a beard should be regarded as a general characteristic of our race, inherited alike by all boys and girls. The development in the female of the reproductive functions at or just before puberty arrests the development of the beard, leaving its power of growth latent in the system for transmission to the next generation, and, as we sometimes observe, to be reawakened to slight growth after the climacteric has been passed. In the same way enlargement of the breasts in the male is arrested at puberty by the development of the male reproductive powers. These facts in heredity apply equally to diseases; for instance, though chorea is not so common in the male as in the female, it, with hysteria and other disorders of childhood, is characteristic alike of boys and girls; while development at puberty of

the reproductive functions has a tendency to arrest the disease in the former, it seems to increase it in the latter.

These facts show clearly that transmission of ancestral peculiarities or diseases, and to a certain extent, of acquired characteristics, forms an influence whose existence cannot be denied, and which in one way or another affects all mankind. For in reality all persons are born with a tendency to many diseases, although there are maladies to which some persons have a tendency, and others none whatever. Such tendency may be either strong and evident to the senses, or weak and faintly marked. It is seen in the former case in those subject to cancer, gout, rheumatism, insanity, spasmodic asthma and deafness; while in some barely perceptible skin diseases, nervous affections and certain cases of mental disorder it is so lightly marked as to be scarcely noticeable. Such slang expressions as "a little off," "slightly wrong in the upper story," "just a wee bit daft," et cetera, indicate this faintly marked departure from the normal. Physicians of all times have recognized the fact that diseases are transmitted from one generation to another, differing in no respect from other hereditary peculiarities. Moreover, a rigid examination of traits, peculiarities, deformities and diseases shows that they are all diseases or deviations from an impossible normal; in other words, that everyone has inherited from his ancestors, simian or human, something which varies from an imperceptible trait to a well-marked abnormality.

Epilepsy is a disease that has for ages arrested attention on account of its tendency to descend from father to son. Romberg says: "In families wherein epilepsy is a pathogenic entail, marriage of the members among themselves should be prevented, and the veterinary principle, of crossing with thoroughbred stock, introduced." In chorea, hereditary transmission of a special susceptibility to nervous irritability has been demonstrated. Mosler says: "Disease of the spleen of a peculiar, specially marked appearance occurs in one-fourth of all cases of hereditary syphilis." Speaking of phthisis pulmonalis, Ruehle says: "If the extent, form and mental qualities can be transmitted in families through generations, why should this not be the case with the conditions which produce a disposition to certain diseases?" Quoting from Charles Darwin's "Origin of Species," "The laws governing inheritance are for the most part unknown. No one can say why the same peculiarity in different individuals of the same species is sometimes inherited and sometimes not; why the child often reverts in certain characteristics to its grandfather or more remote ancestor; why a peculiarity is sometimes transmitted from one sex to both sexes, or to one sex alone, more commonly to the like sex. But hereditary

diseases and some other facts make me believe that the rule has a wide extension, and that when there is no apparent reason why a peculiarity should appear at a certain age, it does tend to appear in the offspring. at the same period at which it first appeared in the parent."

I believe the rule to be of the highest importance in embryology. Let me cite some instances of hereditary transmission. Herbert

Spencer, in his "Biology," mentions the six-fingered Gratio Kellia, who transmitted his peculiarities to several of his children and to some of his grandchildren. The same writer quotes Doctor Struther's description of a woman who had six fingers on one hand and who bequeathed the malformation to some of her descendents for two, three and even four generations. A man inherited from his father an extra digit on each hand and one on each foot. Another who had six fingers and six toes had an aunt and grandmother similarly formed. There are many recorded instances of transmission, from one generation to another of an extra digit, ear, and other organs of the body. Malformations of the external ears, webbed fingers and webbed toes have been perpetuated in the offspring; peculiarities of the skin and its appendages have been transmitted; for instance, every member of a certain family had a lock of hair on the top of the head of a lighter color than the rest. Hereditary baldness is well known. Entire absence of teeth, absence of particular teeth, extra teeth and anomalous forms and arrangements of them are recorded as having been transmitted.

The inheritance of such diseases as gout, rheumatism, consumption and insanity is universally admitted. Icthyosis, leprosy, sebaceous tumors, plica polonica, dipsomania, somnambulism, catalepsy, epilepsy, asthma, apoplexy, elephantiasis and a long list of nervous affections are known to be transmitted from one generation to another. According to Herbert Spencer, a bias toward suicide appears to be hereditary. It cannot be denied that parents transmit to their children developments of structure caused by augmentation of function; otherwise it would be impossible to explain the fact that Bach, Mozart and Beethoven were all sons of musical men. In them the law of evolution, progress from the simple to the complex, or from the general to the special is fulfilled, the children having improved upon their parents. Haydn was the son of a famed organist and Weber's father was a distinguished violinist. Herbert Spencer, who mentions these instances of the fact, says of them: "The occurrence of so many cases in one nation within a short period of time, cannot rationally be ascribed to the coincidence of spontaneous variation; it can be ascribed to nothing but inherited developments of structure caused by augmentation of function."

The tendency of drunkards to transmit to their offspring a love for stimulants is an instance illustrative of this point. Although it is not generally believed that diseases are transmitted directly from parent to offspring, nevertheless it is an accepted fact that the tuberculous patient transmits something to his descendants; it may be a tendency to certain forms of disease or a peculiar weakness of bodily construction in certain directions, or it may be a diminuition of the vis medicatrix naturae. While we cannot state just what it is that is transmitted, we know that a marked susceptibility to the action of various. external agencies is the heritage of the man whose parents on one side or both have been afflicted with tuberculosis, rheumatism, insanity,

et cetera.