Secretary's Report. its grasp. For doing this we have machinery which, if not the most perfect that can be devised, is yet efficient to produce excellent results. Whether such results shall be forthcoming or not is a question, the decision of which rests largely with those to whom the care of the public health is committed, namely, with the local boards of health of Wisconsin and their executive officers. If these boards are properly constituted, and there is no good reason why they should not be, under our existing laws, and if being thus formed, they call to their aid the best sanitarians within their reach as health officers, giving them all requisite support, physical, moral and financial, neither Cholera nor any other form of disease will find within our borders the conditions on which it can thrive. Very respectfully, J. T. REEVE, M. D., APPLETON, Wis., October 28, 1887. Secretary. Disease Germs and Germ Diseases. DISEASE-GERMS AND GERM DISEASES. BY PROF. E. A. BIRGE, PH. D., of the State University, Madison. "In the outer world with which we come into daily contact, the careful observer finds everywhere organisms, which are at the limits of visibility even where the eye is aided by the best microscopes. Small as they are, however, their extended and vigorous activity plays a very important part in the economy of nature and the existence of man. They bring about the decomposition of dead organic substances, effect the oxidation of matters which would else be unchanged, and constantly furnish new food material to the higher or green plants. They bring about the most various kinds of fermentation and are necessary aids in the preparation of common foods and condiments. On the other hand they attack our cultivated plants as parasites and bring decay and death to their hosts: they occasion the severest diseases in higher and lower animals and even threaten man with murderous epidemics. In no department of hygiene is their influence unfelt. In air, soil and water are to be found the same minute organisms which we may recognize in our immediate surroundings, in the house, in the food, and which we occasionally find to be dangerous enemies." With these words Fluegge introduces his exposition of the microoganisms and pictures to us an outline of their far reaching activities and their practical importance to man. In the following pages we shall consider but one group of these microscopic plants, namely the Bacteria. Disease Germs and Germ Diseases. 1. THE FORM AND SIZE OF THE BACTERIA. The Bacteria belong to the very smallest organized beings. A not unusual size is one twenty-five thousandth of an inch in diameter and very few of them over the size of one ten thousandth of an inch, while very many are far smaller than the first named figure, going down indeed to the smallest particles visible in the best microscopes. In form they vary from a sphere to an ellipsoid and so to a rod-like form, or to a long filament. Sometimes these forms occur singly, sometimes they are united in various ways. The little spheres may be joined in strings or in plates or in masses of spheres. The rods may be united by twos or fours into strings longer or shorter, or into long threads. Sometimes these rods are short, sometimes long, they may be stout or slender in proportions, straight or curved. The filaments may be straight, bent at angles, or curved or have a corkscrew form. Whatever be the form of a species of Bacteria its descendents preserve it, the straight rods give rise to their like; as also do the curved forms, the spheres or those of any shape. Spherical forms the botanist calls Micrococcus, the rods, Bacillus, and the curved forms are called Spirillum. 2. THEIR STRUCTURE AND MODE OF REPRODUCTION. Nothing can be simpler than the structure of these minute beings. They have a cell-wall on the outside, a covering of gelatinous matter, sometimes thick, sometimes very thin, outside of this, and inside of it a little living matter in which no structure can be seen. They reproduce in two ways. First by division. The rod elongates and divides into two parts by a cross partition, each new part grows up and similarly divides. The resulting forms may remain connected or separate from each other after a longer or shorter time. If they separate about as rapidly as they divide, we find two or at most three or Disease Germs and Germ Diseases. four rods united. If they remain longer connected we find filaments containing a dozen or more joints. So with the round forms. They may separate as fast as they divide or they may remain connected as before indicated. They may grow out and divide in a line, in which case we get a string of spheres, or they may grow in two directions of space, giving rise to a sheet of cells, or in three directions, forming a cubical packet. The rods always grow in the direction of their length only. This mode of reproduction by division gives rise to the botanical name of the group to which the Bacteria belong - Schizomycetes, or "dividing moulds." A second form of reproduction occurs in the rodlike forms. In the interior of the very minute rod is formed a still more minute spherical or oval body called a spore. It is surrounded by a thick wall and is set free after a time by the bursting of the wall of the cell in which it develops. These spores are usually formed when the medium in which the bacteria are living becomes more or less unfavorable to growth. The round forms have no spores. The reproduction occurs with astounding rapidity. It may take but a few minutes for a cell to reach its full size and divide, so that incredible numbers of individuals may be produced in a day from a single spore. 3. THEIR MODE OF LIFE AND THEIR ABUNDANCE. Bacteria are found in water, air and earth, in food, and in short everywhere where organic nutritive material and moisture occur together. Here they grow and multiply and cause the manifold results of which we shall later tell. In fluids they are found in two conditions of growth. At first they swim freely in the fluid, sometimes swimming actively by a small vibratile filament attached to them, sometimes merely floating. Later they become motionless and collect together either in a mass on the bottom of the fluid or in a coherent film at the top. This is the pellicle so often seen Disease Germs and Germ Diseases. on spoiled milk, soup or other fluid food, and is called by botanists, a Zoögloea. Still more than this: Bacteria are very hard to kill; either the plant itself or its spores are able to resist the destructive agencies of nature - drought and cold. Thus the dust is full of germs, not active but ready to develop as soon as opportunity offers, in the shape of food, moisture and warmth. The may lie thus, dry but ready to grow like seeds, for months or even years. Every pinch of dust from floor or shelf, contains thousands of germs. The air, too, always contains in its dust numerous germs, and in crowded rooms the number is greatly increased. Water, of course contains many of these plants. Every drop of lake, river or cistern water contains them, sometimes but few, usually a great number- often thousands. Water from a quick flowing spring will contain the fewest germs, but no natural water, nor even distilled water, is wholly free from them. 4. THEIR PART IN NATURE'S ECONOMY. We are thus surrounded by a whole world of life whose presence we hardly suspect, but which makes itself daily felt both for good and ill. Such countless millions of creatures have a part to play in the world which is neither insignificant nor unimportant. Nor is it a part which chiefly concerns man directly, though man naturally feels his affairs to be the most important in nature. The bacteria are first of all, promoters of decomposition. Every day countless animals and plants die. Their bodies represent so much food matter withdrawn from the world and now useless to the former owner. Were it not for the activity of the bacteria and their allies, this locked up food - the unavailable capital of life would remain undecomposed and so seriously affect life's possibilities. But no stagnation of life's circulating medium occurs. No sooner is the plant or animal dead than the countless germs of bacteria are ready to swarm and multiply in its body. They consume a little of |