18 - The Cell 



NUCLEOPLASM 



CHROMATIN \ 



PLASMA MEMBRANE 

 NUCLEAR MEMBRANE 



CYTOPLASM 



Fig. 2-2. A typical animal cell 



Fig. 2-3. In a few primitive cells the nuclear 

 and cytoplasmic materials are not separated 

 very distinctly; that is, no distinct nuclear mem- 

 brane is present. In this case the chromatin 

 granules, or chromidia (the most darkly 

 shaded particles in the cells), are more or less 

 scattered throughout the cytoplasm. A, B, and 

 C, cells of different blue-green algae, showing 

 transitional stages in the development of the 

 delimited type of nucleus. (After Acton.) 





i. ■*:■ 



r~r 



.NUCLEI 



Fig. 2-4. Syncytial organisms: 



A, a slime mold, with many 

 nuclei scattered through the 

 continuous mass of cytoplasm. 



B, small portion of filament 

 of a green alga, with many 

 nuclei and chloroplasts scat- 

 tered through the continuous 

 cytoplasm. 



