Kartulis suggests that it may act merely as a carrier of pus-forming bacteria. Others maintain that it is a harmless epiphenomenon, incapable in any way of inducing pus formation. As yet experimental pathology has not given a decisive answer to this, one of the most important questions in tropical pathology, though later experiments are very suggestive. Amœbic dysentery and liver abcesses have been produced in cats by numerous investigators by rectal injection both of amœbic dysenteric stools and sterile liver pus containing amœbæ; these organisms have been demonstrated in the liver pus and intestinal walls of these animals after death. Furthermore, Harris and Gauducheau have been able to produce dysentery and liver abscesses in dogs by similar injections of amœbic pus, the latter by the intravenous route.
Calmette, in view of the frequency with which he and others have found liver abscess to be sterile, suggests that the exciting agency is of a chemical nature, some irritating liquefying body derived from the decomposition processes going on upon the surface of the dysenteric ulcer.
Symptoms.— There is great variety in the grouping of symptoms in liver abscess. The following is a common history: The patient, after residing for some time in the tropics, enjoying good general health and living freely, was attacked by dysentery. In due course he appeared to recover, and resumed work, Several weeks or months elapsed when, after a wetting, or some such incident, he began to feel out of sorts, to suffer from headache, foul tongue, want of appetite, irregularity of the bowels, disturbed nights, excessive and unaccountable languor, irritability of temper, and depression of spirits. About the same time he began to be conscious of a sense of weight and fullness in the right hypochondrium. Later he became feverish, particularly towards evening, the oncoming of the febrile distress being sometimes preceded by a sense of chilliness. At times he had sharp stabbing pain in the right side in the region of the liver, perhaps a dry cough and, possibly, a gnawing, uncomfortable
