368 University of California Puhlications in Zoology \yoh. 20 



This table shows that the cyst wall of Councilmania takes the 

 Congo red stain more readily than that of E. coli. 



In order to place these conclusions on a more accurate basis, a 

 second secies of fifty stools was examined in which the following 

 factors were noted: cysts dead or alive in stool; stool formed or 

 liquid; actual count of cysts on slides to determine more accurately 

 the proportion staining, as well as abundance of cysts in these eases. 



Congo red itself being a very delicate indicator, it was noted 

 whether the stpol became dark in the Congo red, and this was used 

 as the test for acidity. 



Where cysts were abundant one hundred were counted, and the 

 results with the stain noted. But in no case were more than two slides 

 of each specimen examined, as in many cases it would have required 

 examination of ten to fifteen slides to find one hundred cysts. Where 

 one hundred cysts were found on one slide it was considered that 

 the cysts were abundant. Where less than one hundred cysts were 

 found on one slide, but more than fifty cj'sts on two slides, the cysts 

 were considered to be moderately abundant. Where there were less 

 than fifty cysts on two slides the number was considered few, and 

 where less than ten cysts on two slides, very few. 



The results of the second series are recorded in tables 3 and 4. 

 In this series 22 cases, or 44 per cent, were infected with Endamoeba 

 coli, and 28 cases, or 56 per cent, were infected with Councilmania. 

 No mixed infections were inchided in this series. 



TABLE 3 



Series II. Relative Abundance of Cysts of E. coli and Councilmania Cysts 



The contrast between abundance of cysts in infections by Enda- 

 moeba coli as compared with infections by Councilmania is very strik- 

 ing, and is of value because the cysts were actually counted. The 

 three groups of table 1 have been changed to two large groups as being 

 more accurate. Wherever there were less than fifty cysts on two slides 

 it was recorded as few, and where more than fifty cysts were found 

 on two slides the case was recorded as many. 



