The mere presence of amcebw in the stools is not sufficient evidence of the existence of amcebic dysentery. As early as 1870 Lewis and Cunningham found aincebm in the stools of persons sick of cholera in India. They have even been found in the stools of healthy persons (Grassi, -Kruse and Pasquale, Mincke and Roos, Schubcrg). Losch (in 1875) gave the first accurate account of the organism which hc found in the stools of a dysen teric patient, and he studied the intestine removed at the autopsy-. R. Koch ob served amcebm in sections of the intestine of a number of cases of dysentery occur ring in Egypt and India, and suggested a causal relationship between them. Soon afterward (1885) Kartulis was able to find them in more than five hundred cases of endemic dysentery prevailing in Egypt, while they were absent in other diseases. Similar organisms were also found in the contents or walls of amcebie abscess of the liver. The results of Kartulis's studies have been abundantly confirmed in this country by Osier, Coun cilman, Lafleur, Simon, Dock, Eichberg, Howard, Musser, Stengel, Flexner, Wil son, IIarris, and others.
The amcelme coli (s. dysenterim) re sembles in many ways the ammbaa occur ring in the stools of healthy beings. The average size of the latter is from 12 to 36 microns, of the former from 10 to 50 microns. The structure of the two forms is also similar. In a state of rest they appear as slightly-refractive and faintly granular spheres; in the active state a separation into structureless ectoplasm or hyaloplasm and a more refractive, granular, endoplasm or gyanuloplasm takes place. The pseudopodia are ex truded slowly and may be easily ob served; change of position does not al ways follow tbe extrusion. Nuclei are present and often visible, even in the fresh state. This desmiption suffices for the non-dysenteric as well as for the dysenteric varieties; in the latter there is found, in addition, contained within the endoplasm, vacuoles, bacteria, and red blood-corpuscles. The chief constit uent, from a diagnostic stand-point, is blood-corpuscles, as these never occur in the amceke found in healthy- persons; both the vacuoles and bacteria may, how ever, be present. Nothing definite is known of the mode of propagation, but it is believed that multiplication takes place by division.
The anacebm are very little resistant; the stools, etc., must, therefore, be ex amined soon after their evacuation. Their nuniber quickly, diminishes in ma terial outside the body, and at the end of from six to twenty-four hours they ' are often no longer to be found. They have not been certainly successfully cul tivated outside the body in a pure state, although they may have been cultivated along with other micro-organisms (Kar tulis, Celli, and Fiocco).
The evidences for the belief in the causal relationship between the amceba coli and endemic dysentery is summed up by Kartulis as follows: "The con stant presence of the organism in cases of endemic dysentery (with the excep tion of the so-called `Cochin-China diar rhoea'; see below); its presence in the walls of the dysenteric ulcers and absence from other kinds of intestinal ulcers; the successful production of dysentery in cats by the injection of keces containing aniceke into the rectum and even of pus from liver-abscesses free from other mi cro-organisms; the negative results of similar injections (excepting in the ex periments of Celli and Fiocco) of other micro-organisms obtained from dysen teric stools; and, finally, the failure of healthy stools containing amcebm to pro voke dysenteric lesions in cats."
[The recognition of the arricebm in sec tions of hardened tissues and their dis tinction from swelled and degenerated tissue-cells are not always easy. Mallory has introduced a special staining method in which thionin is used, and Harris em ploys toluidin-blue, in order to differ entiate these organisms from other cells. SIMON FLEXNEB.] The endemic dysentery of warm cli mates is probably generated by animal rarasites, is not contagions, and is some times also found in temperate regions. The amceba seems to be the prinoipal factor in its causation, and the patho logical changes produced are most likely due, in part at least, to the bacteria de veloped in Nitn or transported there by the wandering anicebt-e. The direct pa thogenic action of these corpriscles has not yet been satisfactorily established.
Wesener (Rivista Inter. d'Igiene, Sept., Oct., '92).
There are three forms of the organism: (1) the Amata coli fells (Losch), which is the true arnceba of dysentery; (2) the Anurba coli mitts, the cause of the diar rlicea in the second case; and (3) the Aina.ba colt- -elagar's, the form observed in healthy persons. Calomel in small. doses appeared to be the best method of reducing the number of arncebt-e in the stools. Quincke and Roos (Berliner klin. Woch., No. 45, '93).
The anueba dysenterim is distinct from the non-infectious form, or amceba coli. The former, when coupled with bacteria, is the cause of dysentery and of some liver-abscesses. There still re main other liver-abscesses which must be classed as idiopathic, and in which cli matic conditions must be looked on as playing a large part. Among the many questions which are yet to be solved concerning the anicebm are the following: Whether their virulence is constant or can be lost and acquired; how they gain access to the human body; how the bacteria aid tbem; where the bacteria come from; how the dysenteric ulcers begin; whether the predisposing causes of cold and indigestion work on the human organism or on the bacteria; whether there is not also a systemic infection, as well as a local process; in what way the ainceke g,ain access,to the liver, whether along the portal system, the lymphatics, the peritoneum, or the bile-passages. There are certain cases which point to each mode, but in multi ple abscesses the propagation is along the blood-current, either from the ulcers or backward from an original single focus. Kruse and Pasquale (Zeit. f. Hygiene u. Iufectionskr., Feb. S, '94).