384 



BOTAXICAL GAZETTE 



[NOVEMBER 



frequently set up as one of the consequences of a death phenome- 

 non, that is, temporary liquefaction. When C 



AIDUKOV 



at death 



cc 



motion 



reference to ultramicroscopic colloidal particles, and even here this 



motion must sometimes 



the imm 



The consistency of concentrated laboratory glycerine (specific 



high 



in 



It is not always evident that 



in 



ment is to be seen is as high as that of concentrated glycerine 



rule 



that proto- 



in a medium of high consi: 

 in very liauid urotoulasm 



are. As a criterion of 

 the viscosity of protoplasm as a whole I do not regard the occur- 

 rence or non-occurrence of Brownian movement as very accurate 



or conclusive. 



Summary 



1. Protoplasm is a polyphase emulsoid system. 



2. Physical structure and not viscosity determines the sol or gel 

 state of an emulsion. Consequently, while protoplasm undoubtedly 

 exists sometimes as a sol and sometimes as a gel, yet sol and gel as 

 descriptive terms of the physical state of protoplasm must be used 

 with great caution when viscosity is the only criterion. 



3. The viscosity of protoplasm ranges from a degree slightly 

 more than that of water to the firmness of a fairly rigid gel. 



4. While a certain degree of viscosity may characterize the 

 protoplast as a whole, the latter is always more or less divided 

 into regions, whether larger general protoplasmic regions such as 

 ectoplasm and ehdoplasm, or smaller localized centers of proto- 

 plasmic activity such as nucleus and chromatophores, which differ 

 in viscosity from the protoplasm as a whole. 



5. Some protoplasmic regions do not noticeably vary in their 

 consistency, but the viscosity of a protoplast as a whole generally 

 varies considerably within a rather wide range. 



6. Some of the factors influencing changes in protoplasmic con- 

 sistency are periodic changes in physiological activity, develop- 

 ment, reproduction, mitosis, injury, and death. 



