198 PROTOPLASM. 



543. One hundred and seventy-nine grams of fresh proto- 

 plasm of a soft consistence were placed in closely woven linen 

 cloth and subjected to pressure by the hand ; 58 grams of a 

 turbid fluid were expressed ; the mass was then placed under 

 a pressure of 4,000 kilograms, by which 62 grams more were 

 forced out, leaving a drj T cake behind. Thus 66.7 per cent 

 of the mass was pressed out. The fluid thus expressed has a 

 specific gravity of 1.209. That this fluid is intimately incorpo- 

 rated with the more solid portion of the protoplasm, appears from 

 the fact that it cannot be forced from the protoplasm by cen- 

 trifugal force alone. To it the name enchylema has been given ; 

 to the solid matter, the name stroma is applicable. The amount 

 of water contained in fresh protoplasm of ^Ethalium septicum 

 is approximately 71.6 per cent. 



The reaction of protoplasm is alkaline. 



544. In young cells the protoplasm exhibits essentially the 

 same characteristics as those presented b}' the naked protoplasm 

 of the Myxomycetes already alluded to. The phenomena in cells 

 can be most satisfactorily seen in thin-walled plant-hairs. These 

 should be transferred to a glass slide with as little injury as pos- 

 sible, covered immediately with pure water, and examined under 

 a cover-glass which is prevented by bits of wax or thin glass 

 from pressing on the delicate object. The stamen-hairs of Trad- 

 escantia Virginica, pilosa, or zebrina are the best, for in these 

 the cells are sufficiently large to be managed without difficulty, 

 and the walls are perfectly transparent. The cells in the thin 

 leaves of many water-plants answer very well, but they generally 

 contain so much chlorophyll that the protoplasm is obscured. 

 The hairs of the flowers and of the young leaves of plants of 

 the Gourd family and those of the nettle 1 are also excellent 

 objects for the study of protoplasm ; and in general it may be 

 said that almost any plant-hair, if it is young enough and has a 

 thin wall, will serve very well (see Fig. 175). 



545. Protoplasm in cells exists as a nearly colorless mass 



Ammonio-magnesic phosphate 1.44 



Tricalcic phosphate 91 



Calcic oxalate 10 



Chlolesterin 1.40 



Fatty acids extracted by ether 4.00 



Resinous matter 1.00 



Glycerin, coloring-matter, etc 18 



Undetermined matters 5.00 



Huxley : Protoplasm (Half Hours with Modern Scientists, 1871). 



