theory was expressed in the dictum, " Omnis cellula e 

 cellula" That is, the nucleus, becoming gradually elon- 

 gated, at last parted in the midst ; and each half, acting 

 as center of attraction to the surrounding intracellular 

 matrix or contained matter, stood forth as a new 

 nucleus to a new cell, formed by division at length of 

 the original cell. 



The first step taken in resolution of this theory was 

 completed by Max Schultze, preceded by Leydig. This 

 was the elimination of an investing membrane. Such 

 membrane may, and does, ultimately form ; but in the 

 first instance, it appears, the cell is naked. The second 

 step in the resolution belongs perhaps to Briicke, though 

 preceded by Bergmann, and though Max Schultze, 

 Kiihne, Haeckel, and others ought to be mentioned in 

 the same connection. This step was the elimination, 

 or at least subordination, of the nucleus. The nucleus, 

 we are to understand now, is necessary neither to the 

 division nor to the existence of the cell. 



Thus, then, stripped of its membrane, relieved of its 

 nucleus, what now remains for the cell ? Why, nothing 

 but what was the contained matter, the intracellular 

 matrix, and is Protoplasm. 



In the application of this word itself, however, to the 

 element in question, there are also a step or two to be 

 noticed. The first step was Dujardin's discovery of sar- 

 code ; and the second the introduction of the term pro- 

 toplasm as the name for the layer of the vegetable cell 

 that lined the cellulose, and enclosed the nucleus. Sar- 

 code, found in certain of the lower forms of life, was a 

 simple substance that exhibited powers of spontaneous 

 contraction and movement. Thus, processes of such 

 simple, soft, contractile matter are protruded by the 



