6 COMPENDIUM OF GENERAL BOTANY. 



of such great importance that they will be more fully treated in 

 Chapter II. 



The formation of the plasmic utricle is, as has been indicated, 

 not the only differentiation product of the plasm. In the entire 

 plasmic body one can distinguish a fundamental substance (" cyto- 

 plasm" from ^uros", cavity, cell) and inclusions formed within this 

 fundamental substance. These inclusions are of two kinds, (A) 

 living and (B) dead. Tho plasmic utricle and threads constitute 

 the cytoplasm. The living inclusions are the nucleus, the chromato- 

 phores, and the fertilizing elements, made up chiefly of nuclear sub- 

 stance and having a reproductive function. Of the dead substances 

 formed from the plasmic body the most important are protein- 

 grains, protein-crystals, starch-grains, crystals (of fat, salts, organic 

 acids, etc.), oil-globules, and tannin. The term " chromatophores " 

 includes three substances: chlorophyll bodies, color-granules, and 

 colorless starch-builders. These bodies are considered collectively 

 because they are either the bearers of color-substances or are formed 

 out of such to be again converted into chromoplastids. (STRAS- 



BURGER, SCHIMPER.) 



The space not occupied by the above-mentioned solid constitu- 

 ents is filled with a watery fluid, the cell-sap (sometimes having 

 color-substances in solution). 



It is important to bear in mind that within the living cell gas 

 accumulates only in very small quantities. No bubbles are ever 

 rapidly formed. 



The reaction of cytoplasm is usually alkaline or neutral. In the 

 living cell, cytoplasm has the property of reducing very dilute alka- 

 line silver-nitrate solutions. (Low and BOKORNI.) In the cytoplasm 

 an outer hyaline layer (hyaloplasm) and a more granular internal 

 layer (polioplasm) may be noticed. According to REINKE the 

 plasmodia of Aethelium septicum contain 73$ of water, and judging 

 from the mucous nature of other forms of cytoplasm we may con- 

 clude that they also contain a high percentage of water. To plasm 

 in general, especially its important structures, as nucleus and chloro- 

 plastids, one no longer ascribes homogeneity. 1 Careful microscopic 

 examinations reveal a reticulated (spongy) structure of plasm. 

 (SCHMITZ, BUTSCHLI, and others.) 



All life-processes of the cell take place within the plasm. A 



1 I would especially recommend WIESNER'S Elementarstructur, 1892. Trans. 



