52 HUMAN INTESTINAL PROTOZOA IN THE NEAR EAST 



July 15, specimens being examined on eighty-eight days. The 

 case was admitted for dysentery, the stool containing blood and 

 mucus and active amoebae with included red blood corpuscles. 

 Emetin treatment caused the amoebae and symptoms to disappear 

 but relapse occurred, and at this time there were no cysts but only 

 the amoebse as on the previous occasion. Another course of emetin 

 was followed by a similar relapse, while a further course of methyl 

 emetin sulphate had no effect on the infection. As already remarked, 

 on no occasion were cysts of E. histolytica found, though it must 

 be noted that cysts of E. coli were present in small numbers 

 on one or two occasions during the first month of observation 

 a fact which might appeal to those who wish to claim a patho- 

 genicity for E. coli. Why then did not the E. histolytica in this 

 case produce any cysts ? The only explanation seems to be that the 

 case was in a constant state of acute dysentery. The stool was 

 practically always either liquid or unformed, without any adminis- 

 tration of salines, and there was nearly always mucus and often 

 blood mixed with the faecal matter or separate from it. It is 

 interesting to note that a tetramitus infection which was also 

 present on no occasion produced any cysts, and it may be that the 

 unknown factor which prevented the encystment of the E. histolytica 

 prevented also the encystment of the tetramitus. In this particular 

 case, however, the diagnosis was never in doubt, as amoebae with 

 included red blood corpuscles were frequently found. 



It has already been mentioned that several observers have pro- 

 duced dysentery in cats by giving them cysts of E. histolytica by 

 the mouth. We have recently repeated this observation with 

 material from case Carr. There was a very large infection of 

 E. histolytica cysts in fact the largest infection we have come 

 across. There was no history of dysentery whatever, so that the 

 case can be looked upon as a healthy carrier. A small quantity of 

 the stool of this case emulsified in saline was poured into the 

 mouth of a kitten, which was then caged with another of the same 

 age. Both kittens became ill with dysentery and died in a week. 

 In both cases there were numerous amoebae in the large intestine 

 and both showed extensive ulceration. The experiment is valuable 

 in showing that the cysts of E. histolytica in a perfectly healthy 

 carrier, who had no history of dysentery, and who was only dis- 

 covered to be a carrier in the routine examination of healthy men 

 in camp, were capable of giving rise to a fatal dysentery in animals. 

 Furthermore, it is evident that the second kitten contracted infec- 

 tion from the first, probably just after feeding by licking material 



