STRUCTURE OF PROTOPLASM. 



321 



tinguishing between gross and ultimate structure the writer has 

 in mind, under the former, a haphazard arrangement of the 

 minute subdivisions or centers of activity, of the living substance 

 which are at any one moment in differing physiological states; 



DESCRIPTION OF PHOTOGRAPH. 

 A two-needle Barber pipette holder attached to a Leitz microscope. 



while an ultimate structure connotes a definite arrangement of 

 molecules or of the infinitesimal particles seen through the ultra- 

 microscope the microns or inferred amicrons of which all col- 

 loidal systems are composed. 



The most remarkable feature of life within a cell is the coexis- 



