OSMOTIC PROPERTIES OF THE CELL. 45 



profoundly modified in the former by the vital forces which 

 are active in it. 



But the passage of substances from cell to cell may doubt- 

 less take place otherwise than by osmosis. Where the proto- 

 plasm of adjoining cells is continuous, a condition which we 

 saw in the last lecture is probably not uncommon, substances 

 both soluble and insoluble (proteids and fats) in water may 

 be directly conveyed from one cell to another. Again, it 

 frequently happens, as we shall learn in a subsequent lecture, 

 that the hydrostatic pressure which is set up in cells by 

 endosmosis is so great as to cause an escape, a filtration 

 under pressure, of liquid from them. This is probably of 

 importance in the transmission of substances which, though 

 soluble in water, diffuse but slowly. 



BIBLIOGRAPHY. 

 Molecular Structure. 



Naegeli und Schwendener ; Das Mikroskop, 1877. 



Naegeli ; Theorie der Gahrung, 1879. 



Strasburger ; Bau und Wachsthum der Zellhaute, 1882. 



Imbibition. 



Hales ; Statical Essays, Vol. I, 1769 (4th ed.). 



Naegeli ; Pflanzenphysiologische Untersuchungen, Die Starkekorner, 



1858. 

 Reinke ; Unters. lib. die Quellung, in Hanstein's Bot. Abhandl. IV, 



1879. 

 Osmotic Properties. 



Naegeli; Pflanzenphysiol. Unters., Primordialschlauch, 1855. 

 Graham; Chemical and Physical Researches, 1876. 

 de Vries ; Untersuch. iib. Zellstreckung, 1877. 



; Ueb. die Bedeutung der Pflanzensauren fur den Turgor 

 der Zellen, Botan. Zeitg., 1879. 



