



1920] SEIFRIZ— PROTOPLASM 385 



7. Streaming protoplasm is less viscous than quiescent pro- 

 toplasm. 



8. Young active protoplasm increases in viscosity as it matures 

 and becomes less active. 



9. As a Myxomycete Plasmodium prepares to fruit, its consis- 



i 



tency becomes very high. 



10. During mitosis there are very marked regional changes in 

 viscosity. 



11. Physical disturbance usually causes a pronounced increase 

 in viscosity, although the rate of increase varies greatly in differ- 

 ent individuals. 



12. At death protoplasm frequently becomes temporarily very 

 dilute, probably the result of excessive imbibition. Ultimately 

 the degenerate protoplasm coagulates into a solid granular mass, 

 if rapid dissolution has not preceded coagulation. 



* Johns Hopkins University 



Baltimore, Md. 



LITERATURE CITED 



1. Barber, M. A., The pipette method in the isolation of single micro- 

 organisms and in the inoculation of substances into living cells. Phil. 

 Jour. Sci. B. 9:307-360. 1914. 



2. Bayliss, W. M., Principles of general physiology. London. 1918. 



3. Bechhold, H., Colloids in biology and medicine. New York. 1919. 



4* Butschli, O., Protoplasm and microscopic foams. Transl. London. 



5. ^^^llicrodissection studies. L The visible structure of cell proto 

 plasm and death changes. Amer. Jour. Physiol. 43:1-12. 1917. 



6. Chambers, R., Microdissection studies. II. The cell aster: a rever- 

 sible gelation phenomenon. Jour. Exp. Zool. 23:483-504. 1917. 



7. , The microvivisection method. Biol. Hull. 4: 121-126. 1918. 



8. Freundlich, H., Kapillarchemie. Leipzig. 1919. 



9. Gaidukov, N., Dunkelfeldbeleuchtung und Ultramikroskopie in der 



Biologie und in der Medizin. Jena. 19 10. 



10. Garrey, W. E., The nature of the fertilization membrane of Asterias and 



Arbacia eggs. Biol. Bull. 37:287-293. WW- 



11. Hansteix, J., Das Protoplasma als Trager der pflanzlichen und thierischen 



Lebensverrichtungen. Heidelberg. 1880. 



12. Hardy, W. B., t T ber den Mechanismus der Erstarrung in umkehrbaren 



Kolloidsystemen. Zeitsch. Phys. Chem. 33: 326-343- i9°°- 



s 



