AMOEBA OF THE INTESTINAL TRACT. 125 



be very difficult, if not impossible, to demonstrate in 

 the living specimen. During reproduction by gemma- 

 tion the nucleus is seldom visible in the living prepara- 

 tion, but during simple division it can generally be 

 distinguished, lying near the centre of the parasite. 



The characteristic features of the nucleus of Enta- 

 inceba Mstolytica are its lack of a well defined nuclear 

 membrane, the small amount of nuclear chromatin, the 

 minute karyosome, often invisible, and the fact that 

 it is generally invisible or distinguished with great 

 difficulty. 



Vacuoles and Contained Bodies. The endoplasm 

 of this species generally contains one or more vacuoles 

 which are not contractile. In the young parasites a 

 vacuole may be absent, but generally a single one is 

 present, while in the fully developed organisms from 

 one to ten or even more may be present, the average 

 number being two or three. If only one vacuole be 

 present it is of large size and spherical in shape, but 

 if they are multiple the size varies and some of them 

 appear oval in outline. 



In many instances the vacuoles appear to contain 

 bacteria, haemoglobin, small refractile granules, or 

 other material, suggesting that they are digestive in 

 character, but I have never observed any evidence 

 that they are contractile. When the organisms are 

 in motion the vacuoles are continually changing their 

 position within the endoplasm. 



