26 



GENERA I SKETCH OE THE CELL 



some respects thai of l^vitschli, pioloplasin is compounded ol innu- 

 merable minute granules which alone form its essential active basis; 

 and while fibrillar or alvet>lar structures may occur, these are of only 

 secondar\' ii-niionance. 



MS^ 



K, 



m¥m 



A 



;Oa?. -.- 



Fig. 10. — Alveolar or foam-structure of protoplasm, according to Biitschli. [BUTSCHLI.] 



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

 urchin egg. C. Intracapsular protoplasm of a radiolarian ( Thalas sic olio) with vacuoles. 

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

 and water. 



It is impossible here adequately to review the many combinations 

 and modifications of these views which different investigators have 



