46 MACDOUGAL-^ACTION OF LIPOIDS IN GROWTH. 



The control pair of cells are filled with water and set in water 

 giving the endosmostic action of the plasmatic colloids which dissolve 

 into the central cavity. The osmotic action of the salts in cells set 

 in water is illustrative of relative action of the three bases in these 

 cells. The cells containing a salt and saponin in an immersion liquid 

 of saponin were under conditions which would liquefy the lecithin 

 layer and make it as well as the other jellies more permeable to salts 

 of potassium and sodium. The liquefaction of the lecithin in calcium 

 cells apparently was accompanied by the blocking of the larger pores 

 in the clay wall, or by the coagulative action of the calcium on the 

 agar-gelatine jelly and the lecithin. Cells with a lining layer of 

 lecithin only showed a sufficiently low permeability as to give marked 

 amounts of endosmose. 



The above results are of direct interest in showing that if the 

 living cell does have a peripheral layer of lipoids the treatment with 

 saponin might well result in its liquefaction with a resultant radical 

 change in its permeability to salts. The observations of Boas are 

 to the effect that some of the organic contents of the cell may exercise 

 an influence on the action of saponin. 



The principal matter of importance in this connection, however, 

 is the possible effect of the saponin on the cell colloids beside the 

 lipoids which would alter their permeability relations. A series of 

 cells were given the lipoidal treatment, then lined with gelatine-agar 

 jelly. The following results were obtained : 



Contents of cell. Immersion. Excretion or Endosmosis. 



Water Water 8.5 c.c, 8.4 c.c. 



Cane sugar 5 per cent Water 8.7 8.0 



Cane sugar 5 per cent KCl o.oiM 4.5 d.-j 



Cane sugar 5 per cent.") KCl .ooz^M 1.5 1.8 

 Saponin .0025M j " " Saponin .0025M 



The clay walls of the cells are only slowly permeable to sugar 

 and the clay thimble with no lining layer would probably show en- 

 dosmose equivalent to the amount excreted when immersed in water. 

 When the immersion fluid contains potassium chloride the endosmose 

 is the resultant of the opposing action of the salt and sugar. If now 

 the sole action of the saponin were to liquefy the lecithin and render 



