THE CELL DOCTRINE. 73 



as an example. This is, however, very different from 

 a proper membrane."* 



The name protoplasm for the contents of the ani- 

 mal cell had already been brought into use by 

 Remak. 



Leydig,f in 1856, claimed for the contents of the 

 cell a higher dignity than for the membrane or 

 cell wall. He claimed that a cell was but protoplasm 

 (klumpchen-substanz) inclosing a nucleus. The cell 

 membrane, according to him, was simply the hard- 

 ened periphery of the substance of the cell. 



To Max Schultze, however, belongs the credit of 

 having fully overturned the vesicular idea of cells. 

 In 1861,J he insisted upon some modification of pre- 

 vailing views, respecting the relation of cell "wall to 

 cell contents, and contended for a higher position 

 for that part of the cell corresponding to the pro- 

 toplasm of Von Mohl (that within the so-called 

 primordial utricle), and showed how a careful study 

 of the phenomena, presented by the pseudopodia 

 extended b} 7 the various Rliizopods, might aid in 

 clearing up the life of the elements of the cell. 



He also defined the cell as "protoplasm surround- 

 ing a nucleus." The importance of this definition, 

 as stated by Stricker, lay not so much in the fact 

 that many cells were denied a cell wall, as that the so- 

 called cell contents could now be made to harmonize 



* Duffin, loc. citat., p. 252. 

 f Leydig, op. citat. 



J Schultze, Max, Ueber Muskelkorperchen, in Reichert and Du- 

 bois Keymond's Archiv, 1861. 

 % Strieker, op. citat, p. 5. 



7 



