I2O J. F. MCCLENDON. 



substances diffuse out, substances in the- medium (fixing fluids, 

 stains, etc.) diffuse in. There is a more general mixing of tissue 

 substances. Enzymes come in contact with proteids and 

 autolysis results. 



Certain substances are known to increase the permeability 

 of membranes in tissues of the body. Thus ether, chloroform, 

 etc., increase the penetration of fixing fluids, and the exit of 

 contained substances, and the mixing of tissue substances. 

 In this way they increase autolysis. 



II. OSMOTIC PHENOMENA IN PLANTS. 



It is evident that water, salts, carbon dioxide and oxygen 

 can, at least occasionally, penetrate plant cells, as otherwise 

 no growth could occur. In case of the higher plants, the same 

 is true of sugars and other bodies. 1 Janse 2 found that so much 

 KNOs is absorbed by Spirogyra cells in 10 minutes, that it may 

 be easily detected microchemically with diphenylamin-sulphuric 

 acid. 



Osterhout 3 grew seeds of Dianthus barbatus in distilled water. 

 The rate of growth during the several days of observation was 

 normal. In nature, calcium oxalate crystals are found in the 

 root hairs, but are not formed in the distilled water cultures, 

 showing that the Ca comes from the medium. If placed in 

 calcium solutions, crystals became large enough to see with the 

 polarizing microscope in four hours, showing permeability to Ca. 4 



Nathanson 5 found that nitrates and other substances entered 

 the cell. Ruhland also observed penetration of salts. 



Traube-Mengarini and Scala 6 conclude that salts enter plant 

 cells only through the partition walls. At these places there 

 appears an "acid reaction" (bluing of methyl violet). They 



1 See Laurent in Livingstone, "The R6Ie of Diffusion and Osmotic Pressure in 

 Plants," 1903, p. 67. 



1 Versl. en Medeel. der Konikl. Akad. van afdeel. Naturs., 3. Reeks, IV. part, 

 1888. p. 333- 



3 Zeits. f. physik. Chem., 1909, LXX., 408. 



4 But compare von Maycnberg, Jahrb. f. wiss. BoL, XXXVI., 381, who found 

 little penetration of salts into fungous hyphae. And see Demoussy, Comptcs Rcnilus, 

 CXXVIL, 970. 



1 Jahrb. wiss. Bol., XXXVIII., -'84; XXXIX.. 601; XL., 403. 

 6 Biochcm. Zeit., 1909, XVII., 443. 



