﻿88 The Philippine Journal of Science im 



cyst wall. The nuclear structure here also is characteristic. The cyst 

 contains several (from 2 to 8, depending upon the species of entamoeba 

 and the stage of development of the cyst) ring-form nuclei usually smaller 

 than, but of the same structure as, the nucleus of the motile entamoeba. 



I desire to add that the entamoebic cyst wall is of a whitish 

 color and the rest of it is almost invariably of a greenish tint 

 under the 3 objective. 



DIFFERENTIAL DIAGNOSIS 



In the performance of the work herein recorded, I have 

 repeatedly made provisional differential diagnosis upon quies- 

 cent and active entamoebae occurring in ordinary and in 

 diarrhoeal stools, particularly those produced artificially by mag- 

 nesium sulphate. Subsequently, formed stools were obtained 

 from those cases, and differential diagnosis rendered upon en- 

 cysted entamoebae. The exact number of cases in which this 

 procedure was adopted cannot be given, but certainly it was not 

 less than fifty. The result was a thorough conviction that ordi- 

 narily I, at least, cannot make a correct differential diagnosis 

 upon either the quiescent or active forms in question. While 

 active organisms seen in pronounced dysenteric stools can usually 

 be differentiated, the one stage of development in which two 

 distinct species can be discerned is the completely encysted one. 

 For the detailed points of differentiation of the two species, the 

 reader is referred to Walker's article.^- Walker summarizes the 

 differential points in a general way as follows : 



Motile stage. 



B. Entamoeba coU. 



1. Appearance porcelaneous. 



2. Refractiveness more pronounced. 



A. Entamceba hiBtolytica. 



1. Appearance hyaline. 



2. Refractiveness more feeble. 



3. Movements active in the fresh l 3. Movement sluggish 



stools. I 4. Nucleus distinct. 



4. Nucleus more or less indistinct. 5. Chromatin of nucleus abundant 



5. Chromatin of nucleus scanty. 



Encysted stage. 

 A. Entamoeba histolytica. 



1. Cyst smaller. 



2. Cyst less refractive. 



3. Cyst usually contains elongated 



refractive bodies known as 

 "chromidial bodies." 



4. Nuclei never more than 4. 



5. Cyst wall thinner. 



B. Entamoeba ooU. 



1. Cyst larger. 



2. Cyst more refractive. 



3. Cysts do not contain "chromidial 

 bodies." 



4. Nuclei 8, occasionally more. 



5. Cyst wall thicker. 



"Ibid (1913), 8, 317. 



