i8 



GENERAL SKI: TCI I ()/' Till'. CELL 



zoologists and botanists regard protoplasm as essentially a liquid, or 

 rather a mixture of liquids, which forms a foam-like alveolar structure 1 

 like an emulsion, in which the firmer portion forms the walls of sepa- 

 rate chambers, filled with the more liquid substance (Fig. 8). By 



Fig. 8. Alveolar or foam-structure of protoplasm, according to Biitschli. [BiJTSCHLI.] 

 A. Epidermal cell of the earthworm. B. Aster, attraction-sphere, and centrosome from sea- 

 urchin egg. C. Intra-capsular protoplasm of a radiolarian (Thalassicolla) with vacuoles. 

 D. Peripheral cytoplasm of sea-urchin egg. E. Artificial emulsion of olive-oil, sodium chloride, 

 and water. 



special local modifications of this structure all the parts of the cell are 

 formed. Btitschli has shown that artificial emulsions, variously pre- 

 pared, may show under the microscope a marvellously close resem- 



1 " Wabenstrn klur." 



