CELL THEORIES. 123 
chareacters of protoplasm and distinct from the 
nucleus. 
One of the short-comings of Professor Stricker’s 
article on the general character of cells is that he 
exaggerates the virtue of the protoplasm. He uses 
the expression, “ Protoplasm is termed a living 
substance,’ or, as the German (man bezeichnet) 
may be more strictly translated, “it is recognized 
? 
as a living substance ;” and he speaks in such a 
way as to leave the impression that it is a definite 
chemical compound. Now, the fact is that proto- 
plasm when examined under the microscope, is 
usually as thoroughly dead as anything could be 
well imagined to be. Living masses of protoplasm, 
no doubt, can be studied microscopically, and a 
great stride has been made in science by the ex- 
amination of such masses in texture; but the com- 
position of the protoplasm is not definitely known. 
It is quite unobjectionable to call the albuminoid 
mass of a nucleated corpuscle protoplasm, even 
after it has been acted on by means of chromic 
acid, carmine, or other reagents. In fact, proto- 
plasm is simply a convenient name to use in speak- 
ing of the pulpy nitrogenous substance of vital 
corpuscles ; but it is not to be forgotten that the 
substance referred to is variable in appearance and 
behaviour, as is well illustrated by Heidenhain’s 
