2. Diseases and Injuries of the Larynx and Trachea. 3. Operations on the Larynx and Trachea .. 4. Diseases and Injuries of the Chest, Pleura, and Lungs. 605 XXVI. DISEASES AND INJURIES OF THE UPPER DIGESTIVE TRACT 612 3. Diseases and Injuries of the Urethra, Penis, Testicles, MODERN SURGERY. I. BACTERIOLOGY. BACTERIOLOGY is the science of micro-organisms. Though a science in the youth of its years, bacteriology has not only profoundly altered, but it has also revolutionized, pathology, and our views of surgery will be incomplete, misleading, and erroneous without its aid. Micro-organisms, microbes, or bacteria, are minute vegetable cells of the class fungi, many of them being visible only by means of a highly powerful microscope after they have been brightly stained. The contents of these cells are protoplasm and-nuclear chromatin enclosed by a structure containing cellulose. The protoplasm can be stained with anilin colors, and the cell-wall is more readily detected after treating it with water, which causes it to swell. Many organisms are colored, others are colorless. Some move (motile bacteria), others do not move (amotile bacteria); among the motionless ones may be mentioned the bacilli of anthrax and tubercle, and all cocci. Many bacteria can change from motile to amotile or from amotile to motile when subjected to changed conditions of life. The oscillations of cocci are physical and not vital in nature; they are Brunonian movements, movements due to alterations in equilibrium because of currents or changes of level in the fluid in which the organisms are held. Bacteria possess the power of attracting elements necessary for their nutrition and of repelling elements antagonistic to them (chemiotaxis or chemotaxis). Definite knowledge of these minute bodies and of their actions dates from the study of fermentation by the celebrated Frenchman Pasteur, who in 1858 asserted that every fermentation has invariably its specific ferment; that this ferment consists of living cells; that these cells produce fermentation by absorbing the oxygen of the substance acted upon; that putrefaction is caused by an organized ferment; that all organized ferments are carried about in the air; and that to entirely exclude air prevents putrefaction or fermentation. These statements, which were radical departures from accepted belief, inaugurated a bitter controversy, and in that controversy were born the microbic theory of disease, the doctrine of preventive inoculation, antiseptic surgery, and serum-therapy. The word microbe, which signifies a small living being, was introduced in 1878 by the late Professor Sédillot, of Paris. At that time the nature of these bodies was in doubt; some thought them animal, and called them microzoaria; others thought them vegetable, and called them microphyta; the designation "microbe" does not commit us to either view. We now know them to be vegetable, but the term "microbe" has remained in use. The fungi connected with disease in man are divided into three classes: 1. Yeasts, Saccharomyces, or Blastomycetes; 2. Moulds, or Hyphomycetes; 3. Bacteria, or Schizomycetes. Yeasts include most of those fungi which can cause alcoholic fermentation in saccharine matter. They consist of small cells which multiply by gemmation and which can live without free oxygen. These cells often stick together and form branches, and contain spores when nourishment is insufficient. They are thought to be vegetative forms of higher fungi (Green). The chief importance of yeasts is that they cause fermentation; they never invade human tissues, though they can dwell on mucous membranes, and even in the stomach. Oidium albicans is an yeast-fungus whose growth upon the mucous membrane of the mouth, pharynx, and esophagus causes the disease known as "thrush." Pekelharing says that pityriasis capitis is due to the saccharomyces capillitii. Moulds consist of filaments, each filament being composed of a single row of cells arranged end to end, and all filaments springing from a germinal tube which grows from a germinating spore. Moulds are largely connected with processes of decay. Some of them grow upon inflamed mucous membrane, and some invade the epidermis, producing certain skin diseases (favus, tinea tonsurans, tinea versicolor, etc.). Actinomycosis and Madura-foot arise from the lodgement and growth of moulds (Fig. 1). Actinomycosis is a disease seen in cattle, and occasionally in men, especially in drovers. Cattle become infected usually through their food, the fungus entering by a hollow tooth or by a breach of continuity in mucous membrane. The lower jaw is usually the seat of involvement in cattle (lumpy jaw). A tumor forms, which contains sero-pus, and after a time ruptures and discharges matter containing nodules composed of fungi. The bone may undergo extensive destruction. Other bones and various organs may be infected. Madura-foot or mycetoma is an endemic disease of India, which is probably due to infection with the Chionypha Carteri. The foot swells and becomes covered with pustules; the pustules rupture and expose sinuses; each sinus is lined with a firm membrane and is filled with material which looks like the roe of a fish. The bones are often extensively destroyed, and gangrene not uncommonly arises. FIG. 1.-Actinomyces (Ziegler). Bacteria chiefly claim our attention. It is important to remember that the term "bacteria," though applied to the class schizomycetes, has also a more restricted applicationthat is, to a division of the class; it may mean either schizomycetes in general, or rod-shaped schizomycetes, whose length is not more than twice their breadth. Some of the schizomycetes induce certain fermentations; others grow upon dead organic matter, but are not able to invade living tissues, and are called saprophytes or nonpathogenic bacteria; still others, known as the pathogenic, cause various diseases. Parasitic bacteria can grow on or in the tissues of the body. Obligate parasites are those which have not been cultivated outside of the body (as the bacilli of leprosy). Facultative parasites usually live outside the body, but may enter into the body and produce disease. The schizomycetes vary much in shape, size, color, arrangement, mode of growth, and action upon the body. One form cannot be transformed into another, but each maintains its specific identity. Every organism comes from a pre-existing organism, this being true of all forms, as spontaneous generation is impossible. Forms of Bacteria.-The three chief forms of bacteria are 1. The Coccus or Micrococcus-berry-shaped, oval, or round bacterium (Fig. 2); 2. The Bacillus-rod-shaped bacterium (Fig. 3); 3. The Spirillum-corkscrew-shaped or spiral bacterium (Fig. 4). A short spiral is called a comma bacillus. De Bary compares these forms, respectively, to the billiard-ball, the lead-pencil, and the corkscrew. Cocci and Bacilli.-We have to do only with cocci and bacilli. Cocci may be designated according to their arrangement with one another; namely, when existing singly they FIG. 2.-Micrococcus. た FIG. 3.-Bacillus. FIG. 4.-Spirillum. are called monococci; in pairs they are called diplococci (Fig. 5, A); in a chain they are called streptococci (Fig. 5, c); in a cluster like a bunch of grapes they are called staphylococci (Fig. 5, B); in groups of four they are called tetracocci; in groups of eight they are called sarcina or wool-sack cocci. Irregular masses, resembling frog-spawn, constitute zoöglea masses (Fig. 6). The gelatinous matter in such a mass is formed by a transformation in the walls of the bacteria. The term ascococci is applied to a group of cocci enclosed in a capsule (G. S. Woodhead). The cocci are often named according to their function, as, Cocci may be for example, " pyogenic," or pus-forming. named according to the color of the culture. The name may embody the form, arrangement, color, and function; for instance, staphylococcus pyogenes aureus signifies a round, golden-yellow micro-organism, which arranges itself with its |