44 THE CELL DOCTRINE. 



vesicular composition of plants, and yet failed to ap- 

 preciate the importance of the-nucleated cell, and to 

 deduce from it a law of development applicable to 

 all organic forms. Again, as the engine of "Watt was 

 far different from the beautiful and powerful crea- 

 tion of the mechanic of the present day, so the cell 

 theory, as developed by Schleiden and Schwann, has 

 been further evolved by later histologists, We 

 may therefore truthfully reiterate, with Prof. Hux- 

 ley, that " whatever cavillers may say, it is certain 

 that histology before 1838, and histology since then, 

 are two different sciences — in scope, in purpose, and 

 in dignity — and the eminent men to whom we allude, 

 may safely answer all detraction by a proud ' circum- 

 spice.' "* 



,^ According to these observers, then, a perfectly 

 formed cell would be defined as a closed vesicle, with 

 certain contents, among which were essentially a nu- 

 cleolus and nucleus. .. 



HBNLE, BBRGMANN, REICHERT, AND OTHERS, 1840-46. 



It is not consistent with our object to include all 

 of the numerous observations which were multiplied 

 after this period, incited by the researches of Schlei- 

 den and Schwann. It is simply to point out the 

 salient features of those results which point towards 

 and have culminated in accepted views. It has been 

 stated that previous to Schleiden's researches, in 

 1838, the formation of cells by division had been as- 

 serted as one mode of origin, that Schleiden had de- 

 clared this an error of observation, and that Schwann 



* Huxley, op. citat., p. 290. 



