LOESCHIA 



315 



by Hartmann under the heading E. tetragena, and often called the 

 tetragena phase. It resembles the histolytica phase in many par- 

 ticulars, but differs therefrom in the fact that the nucleus is usually 

 clearly visible as a well-rounded globular vesicle plainly set off from 

 the cytoplasm by a stout double contoured membrane and showing 

 in the middle a small karyosome, surrounded by a clear structure- 

 less zone, between which and the nuclear membrane there is a linin 

 network on which granules of chromatin are distributed. 



Fig. 55. — Loeschia histolytica Schau- Fig. 56. — Loeschia histolytica, Schau- 

 DiNN, Young Trophozoite Fixed dinn, Old Trophozoite or 

 AND Stained, showing Nucleus . Tetragena Phase. Stained 

 AND Phagocyted Red Blood j' Preparation, (x 1,950 Diam- 

 Cells, (x 1,950 Diameters.) eters.) 



(After James.) 



This nucleus undergoes cyclical changes, but in a given prepara- 

 tion, as a rule, all the amoebae show the same appearance. The 

 cyclical changes are:' — ■ 



1. Large blocks of chromatin under the nuclear membrane, a very 

 definite karyosome containing a centriole (Fig. 57, a, and 58, a). 



2. Many small granules of chromatin scattered under the mem- 

 brane and at the margin of the karyosome (Fig. 57, h). 



Fig. 57. — Nucleus of Loeschia histolytica Schaudinn, Old Trophozoite 

 Phase. Stained Preparations, (x 1,950 Diameters.) 

 (After James.) 

 Note the cyclical changes described in the text. 



3. Chromatin more concentrated under the nuclear membrane 

 and at the karyosome margin, while a clear zone is appearing around 

 the centriole (Fig. 57, c). 



4. Chromatin under the membrane and at the karyosome margin 

 (Fig. 57. d)- 



