PART II. CHARACTERS AND DIAGNOSIS 49 



Case Russell, F. (Plate I, figs. 7-9).* 8, 7, 8, 7, 7, 8, 9, 8, 7, 8, 

 6, 7, 8, 7, 8, 7, 8, 7, 8, 6, 9, 8, 7, 8, 7, 8, 8, 8, 6, 8, 8, 9, 8, 8, 8, 8, 7, 

 8, 8, 8, 8, 7, 8, 8, 7, 8, 8, 7, 9. 



Case Kettle well. 10, 9, 8, 10, 8, 9, 8, 7, 10, 9, 9, 9, 10, 9, 10, 10, 



10, 9, 8, 10, 9, 11, 8, 9, 8, 10, 9, 8, 8, 9, 10, 8, 9, 9, 12, 10, 9, 10, 10, 



11, 10, 8, 8, 9, 10, 8, 11, 10, 9, 9. 



Case Cooper. 10, 12, 12, 11, 12, 12, 12, 13, 11, 13, 12, 10, 12, 13 

 10, 12, 13, 11, 12, 14, 12, 12, 9, 13, 12, 12, 12, 11, 11, 12, 12, 11, 12, 

 13, 12, 13, 11, 11, 12, 10, 12, 10, 12, 12, 13, 12, 11, 11, 13, 12. 



Case Noon. 14, 14, 14, 14, 13, 12, 13, 14, 13, 12, 12, 13, 12, 13, 

 11, 14, 13, 14, 15, 12, 12, 15, 14, 14, 12, 12, 12, 12, 12, 12, 12, 13, 13, 



15, 12, 10, 14, 12, 12, 14. 



Case Flynn (Plate I, figs. 4-6).* 14, 12, 12, 12, 13, 12, 12, 12, 14, 



14, 13, 14, 14, 12, 12, 11, 13, 14, 14, 12, 14, 14, 12, 11, 13, 12,13, 14, 



12, 14, 13, 12, 15, 14, 10, 12, 14, 12, 14, 12, 14, 12, 14, 14, 15, 13, 11, 

 12, 14, 13. 



Case Healy (Plate I, figs. 1-3).* 16, 18, 14, 14, 12, 14, 1, 18, 14, 



16, 16, 14, 18, 18, 18, 14, 16, 16, 16, 15, 16, 15, 14, 15, 14, 16, 14, 16, 

 18, 18, 16, 15, 16, 12, 14, 14, 15, 12, 12, 13, 17, 14, 14, 16, 16, 14, 12, 



15, 16, 14. 



The figures (Plate I, figs. 1-9)* represent cysts with one, two, and 

 four nuclei drawn to the same scale from three of the above cases. 

 They show graphically the great difference in size of these various 

 strains. It may, however, be safely stated that the majority of 

 cases of E. histolytica infection show cysts with a diameter of 

 10 to 14 microns, but one must always be careful to recognize 

 the smaller and larger strains, for they have to be carefully 

 distinguished from cysts of E. nana on the one hand and cysts 

 of E. coli on the other. 



The cysts of the large strains differ from the cysts of E. coli in 

 the more frequent possession of chromidial bodies and the constant 

 presence of not more than four nuclei. 



As regards the virulence of the different strains and their reac- 

 tions to emetin we can make no very precise statements. Case 

 Kettlewell, who had the small strain, did not clear up on injections 

 of one grain of emetin for twelve days, but did on subsequent treat- 

 ment by the mouth, and case Healy, who had the largest strain, 

 was the most resistant case we had had, and withstood not only 

 emetin injections, but also emetin and pulv. ipecac, by the mouth. 



* See inset between pages 148 and 149. 



