Chapter II 



7 — 



General Facts 



which impregnate the cytoplasm and can be detected only by using 

 certain microchemical reagents. All these products arise by cjrto- 

 plasmic activity and a distinction must therefore be made between 

 them and the cytoplasm by which they were pro- 

 duced. These products are grouped under the 

 term pm'aplasm or deutoplasm and are separated 

 from the cytoplasm, which, with the plastids and 

 chondriosomes, constitute living substance. Among 

 the products resulting from the activity of the 

 cytoplasm are some which are of permanent char- 

 acter, such as the cellulose wall. This is a cyto- 

 plasmic secretion which persists during the entire 

 life of the cells and can not, it would seem, be 

 considered as belonging to living substance. 

 These permanent formations of the paraplasm or 

 deutoplasm are specified as metaplasm. Lastly, 

 the name protoplast is used to designate all the 

 contents of the cell except the cell wall, i.e., the 

 protoplasm and paraplasm together. 



In the cytoplasm, then, we shall have to con- 

 sider the cytoplasm itself, the plastids, the chon- 

 driosomes and the paraplasm, the most important 

 constituents of the last category being the vacu- 

 oles and the lipide granules. 



These, and other paraplasmic formations not listed above, will 

 be studied in the succeeding chapters. 



Fig. 2. — Semidia- 

 grammatic represen- 

 tation of a living 

 epidermal cell of Al- 

 lium. Cepa showing 

 cytoplasmic trabecu- 

 lae traversing the 

 vacuole and uniting 

 the parietal cytoplasm 

 with the nucleus. 



