AMOEBAE OF THE INTESTINAL TRACT. 95 



from the chromatin, is apparently composed of fluid 

 material enclosed in a very delicate achromatic net- 

 work. 



When the organisms are in motion the nucleus 

 tends to retain its position near the centre, although 

 at times it may be observed at the periphery of the 

 moving parasite. 



In some instances the limiting membrane of the 

 nucleus is very thick and perfectly smooth in out- 

 line, while the chromatin is collected in irregular 

 masses within the membrane, the karyosome being 

 indistinguishable. This appearance is especially 

 noticeable just prior to encystment and does not occur 

 during the vegetative stage of existence. Again, 

 amoeba? are observed in which the chromatin is 

 arranged in very irregular masses upon the inner 

 surface of the nuclear membrane or close to it, while 

 the karyosome is well differentiated. Many different 

 appearances as regards the situation of the chromatin 

 are presented by the nucleus in various stages of 

 development, but the most common are those which 

 have been described. 



Stained Preparations. The methods which may 

 be used for staining Entamceba coli have already been 

 described, but I have found that Wright's method 

 and iron hsematoxylin give the best results. I have 

 observed but little difference in the results obtained 



