374 * BOTANICAL GAZETTE [November 



is not of as low viscosity as it superficially appears to be, and by 

 no means closely approaches the very liquid state of the endoplasm 

 of an active Amoeba. In its most fluid condition it is of at least 

 a rather viscous consistency (v. v. 5), while, when slowly streaming, 

 it may be of very viscous consistency (v. v. 7). All gradations 

 exist between the rather viscous condition when streaming and the 

 gel state when quiescent. 



Increase and decrease in viscosity of protoplasm in Rhizopus 

 are probably dehydration and hydration phenomena. It is inter- 

 esting to appreciate the extreme rapidity with which these changes 

 may take place. The streaming protoplasm, by pressure of a 

 needle sufficient to close a hypha, may be made to assume instantly „ 

 such a consistency that not only does streaming cease, but on sub- 

 sequent tearing of the filament the emptying of the thread is 

 prevented. Choking of the hypha has caused gelation of the 

 plasma, probably through dehydration. Later, without further 

 disturbance by needles, there is a reversal of the phenomenon. 

 Solation takes place (apparently hydration has set in) and the 

 protoplasm of itself flows out of the torn filament. 



Euplotes 



In the ciliate Euplotes there exists a differentiation between 

 endoplasm and ectoplasm more marked than in any other instance 

 of which I am aware. The endoplasm is very liquid, while the 

 ectoplasm has the firmness of a rigid gel. The former consists of 

 a dilute matrix in which a great variety of inclusions are suspended, 

 from minute protoplasmic particles to whole Protozoa taken in as 

 food; while the latter is free of minute granules (microsomes), 

 and presents a beautiful alveolar structure with the characteristic 

 surface alveolar layer. So far as my limited observations on this 

 protozoan go, the very liquid condition of the endoplasm and the 

 gel state of the ectoplasm seem to be constant. I have observed 

 no change from sol to gel and vice versa, nor any appreciable 

 increase or decrease in viscosity. That there must be some such 

 change at division of the organism (for example, solation of the 

 rigid ectoplasm) seems a physical necessity. 



