128 THE CELL DOCTRINE, 



acter. So that the term " cell " is really no longer a 

 correct one, since the object to which it is applied is, 

 in its youngest, most active state, at least, a solid 

 mass or "clump " of .living matter without the ves- 

 tige of a wall or envelope about it. The word has, 

 however, become so intimately associated with his- 

 tology that it is doubtful whether it will ever fall 

 into disuse, nor does it much matter, so long as cor- 

 rect notions of the elementary part are obtained. 

 This latter term, " elementary part," is, however, to 

 be preferred. 



Consistently M'ith the latest determined facts, the 

 cell or elementary -part is best defined as the smallest 

 mass of living matter possessing the essential life prop- 

 erties of reproduction, nutrition, growth, and develop- 

 ment. To such substance the terms " sarcode," " pro- 

 toplasm," "germinal matter," and "bioplasm" have 

 been applied, the first by Dujardin, the second by 

 Max Schultze and Eemak, and the third and fourth 

 by Eeale. 



The term " sarcode " has nearly gone out of use, 

 and " protoplasm " has come to be largely used for 

 that part of the cell outside of the nucleus, without 

 regard to its living properties. The term " bioplasm," 

 on the other hand, has not yet received such exten- 

 sion of meaning, while it also etymologically defines 

 the substance it represents, and is therefore much to 

 be preferred. 



The Nucleus of the Cell. — Tn the interior of most 

 cells are found one or more difli'erentiated masses of 

 bioplasm, usually round or nearly so, and more gran- 

 ular or darker in hue by transmitted light than the 



