30 THE ANIMAL PARASITES OF MAN 



into Eichwald's clinic at Petrograd with symptoms of dysentery. In the dis- 

 charges containing blood and pus, Losch found amoebae in large numbers. When 

 at rest these amoebae measured from 20 A* to 35 /t ; in a state of movement their length 

 might extend up to 60 /* (fig. i). The pseudopodia appeared only singly, and, 

 since they were hyaline (ectoplasmic), were thus distinguished from the markedly 

 granular endoplasm that enclosed a spherical nucleus of from 5 /u to 7 p. in diameter. 

 One or more non-contractile vacuoles were present. Quinine enemata had the 

 effect of making the amoebae disappear from the faeces and thus causing the diarrhoea 

 to abate. Four months after admission the patient died from the results of 

 intercurrent pneumonia. At the autopsy ulceration of the large intestine was found, 

 especially in the lower parts. Losch connected the amoebae with the ulcerations by 

 experiments made on four dogs by injecting them with recently passed stools 

 (per os et anum}. Eight days after the last injection numerous amoebae were found 

 in the faeces of one of these dogs ; eighteen days after the injection the animal 

 was killed. The mucosa of the rectum was inflamed, covered with blood-stained 

 mucus and ulcerated in three places. Numbers of amoebae were found both in 

 the pus of the ulcers and in the mucus. The three other dogs remained healthy. 

 From these observations Losch concluded that the species of amoeba described by him 

 as Amccba coli could not be regarded as the primary cause of the disease, but that it 

 was certainly capable of increasing a lesion of the large intestine already present, 

 or at least of preventing its healing. 



B. Grassi (1879) found in the stools of healthy as well as in those of diarrhceic 

 patients from various localities in Northern Italy, amoebae similar to those discovered 

 by Losch. As this was of frequent occurrence, the pathogenicity could not be 

 definitely established. Normand, formerly naval surgeon at Hong-Kong, observed 

 numerous amoebae in the dejecta of two patients suffering from colitis. 



Many further investigations, which cannot be quoted in detail, showed not only 

 that intestinal amoebae were widely distributed in man, but indicated with greater 

 certainty their role as agents of dysentery. The Commission sent out by the German 

 Government in the year 1883 to investigate cholera in India and Egypt whose 

 members discovered the cholera bacillus also collected information with regard to 

 dysentery. In five cases of dysentery examined post mortem at Alexandria, with 

 the exception of one case in which ulcerati6n of the colon had already cicatrized or 

 was approaching cicatrization, R. Koch found amoebae as well as bacteria in sections 

 from the base of the ulcers, although such had previously escaped notice in examina- 

 tion of the dejecta. Encouraged by these results, Kartulis (1885), who had discovered 

 amceba-like bodies in the stools of patients suffering from intestinal complaints at 

 Alexandria, continued his investigations. The results, obtained from more than 500 

 cases, gave rise to the theory that typical dysentery was caused by amoebae as were 

 also the liver-abscesses that often accompany it. Kartulis supported his theory not 

 only by the regular occurrence of amoebae in the stools of dysenteric patients and 

 their absence in other diseases, and by the occurrence of the parasites in ulcers of the 

 large intestine and in the pus from liver-abscesses, but also by experiments which 

 he performed on cats. These were infected by injection per anum of stool material 

 rich in amoebae from subjects of dysentery. The infection took place also when 

 amoeba-containing, but bacteria-free, pus from liver-abscesses was used. It has been 

 objected that the infection of man with Amazba coli, as the dysenteric amoebae were 

 then generally designated, does not take place per anum \>\\\. per os. This difficulty, 

 however, diminished in proportion as the encysted states of amoebae (fig. 2), long 

 known in the case of other Protozoa, became understood. The infection of man 

 (Calandruccio, 1890) and of cats (Quincke and Roos) succeeded solely when material 

 containing such stages was used. Amoebae introduced into the intestine multiply 

 thereby fission (Harris, 1894). However, this theory, to which various other authors 



