858 PROGRESS OF SCIENCE IN THE CENTURY. 



he was the first to call "protoplasm") with the 

 " cambium " of plant cells ; in 1846 Von Mohl em- 

 phasised the importance of the " protoplasm " in veg- 

 etable cells; Ecker (1849) compared the contractile 

 substances of muscles with the living matter of 

 Amoeba; Donders also referred the contractility from 

 the wall to the contents; Cohn suspected that the 

 " sarcode " of animals and the " protoplasm " of 

 plants must be " in the highest degree analogous sub- 

 stances"; and finally, Max Schultze (1861) ac- 

 cepted the growing belief that plants and animals 

 were made of very similar living matter, and defined 

 the cell as a unit mass of nucleated protoplasm.* 



"The full physiological significance of protoplasm, 

 its identity with the ' sarcode ' of the unicellular forms, 

 and its essential similarity in plants and animals, was 

 first clearly placed in evidence through the classical 

 works of Max Schultze and De Bary, beside which 

 should be placed the earlier works of Dujardin, Unger, 

 Nageli, and Mohl, and that of Cohn, Huxley, Virchow, 

 Leydig, Briicke, Kuhne, and Bealc." f 



Louis Agassiz, not being an evolutionist, spoke of 

 the cell-doctrine as "the greatest discovery in the 

 natural sciences in modern times " ; and, apart from 

 the idea of evolution, it may be called the most in- 

 fluential. For it is important to notice that it has 

 cot only affected the analysis of the anatomist and 

 the physiologist, and the whole of embryology, but 

 has entirely changed our position in regard to some 



See the writer's Outlintt of Zoology, Introduction, 

 t E. B. Wilson, The CtU in Development and Inheritance, p. & 



