98 PROTOPLASM HISTORY SINCE 1860. 



This need not detain us, being now superfluous. He agrees 

 with Pringsheim that the supposed primordial utricle, as a 

 separate membrane, has no existence in the vegetable cell, and 

 that the outer layer is merely protoplasm, as we saw Naegeli 

 stated long before. He gives his own observations showing 

 there is a similar outer layer of protoplasm in the animal cell 

 which cannot be called a membrane, even when no distinct 

 separation between the protoplasm layer and intracellular fluid 

 takes place, as in fact it does more seldom than in the plant 

 cell. In short, he considers established the fundamental 

 analogy of the plant and animal cell as regards the protoplasm. 

 He considers that the cell may be denned as consisting of a 

 little mass of protoplasm and a nucleus, and that these consti- 

 tute a single whole, and that the nucleus plays an important 

 part, although he confesses what that may be is not as yet 

 sufficiently known. He shows, also, that the movements of the 

 pseudopodia and the granules are produced by active con- 

 tractile movements of the protoplasm, as had been hypotheti- 

 cally supposed by Unger. In 1860 he had already used these 

 words : " I finally proposed to banish entirely the word Sar- 

 code, which was repugnant as standing to a certain extent in 

 opposition to the cell theory, and to substitute for it the word 

 protoplasm, in which is expressed the triumph of the cell theory 

 over these lowest organisms also," i.e., the Rhizopoda, which 

 naturalists had found difficult to bring under the cell theory 

 (with good reason, as we think still). In the essay of 1861 he 

 says " The opinion may be defended that the formation of a 

 chemically different membrane on the surface of the protoplasm 

 is a sign of commencing retrograde metamorphosis, and that 

 the cell membrane belongs so little to the conception of a cell, 

 that it may even be looked on as a sign of approaching de- 

 crepitude, or at least of a stage in which the cell has already 

 suffered a considerable loss of its original vital activity." This 

 was violently attacked by his German critics, and now (1863), 

 after reading Beale, he does not re-affirm it with increased 

 decision, but, on the contrary, draws back and apologizes' for it 

 as an opinion which one might defend as a whim (aus Laune). 

 M. Schultze concludes his book in the following words " I 



