326 PROPERTIES OF THE COLLOIDAL CONSTITUENTS 



ity in each solution was determined. The results showed that the 

 ratio ^g *^ was constant over a wide diversity of concentrations. 

 In other words the concentration of bivalent ions necessary to preserve 

 motility varied directly as the concentration of monovalent ions and 

 not as the square, as in the case of permeability. While motility, 

 therefore, is affected by changes in permeability, the effects upon 

 motility involve changes which are not identical with those which 

 underlie the alterations of permeability. 



The permeability of the surface of the cell for substances dissolved in 

 water is presumably determined by the diameter of the interstitial 

 pores filled with protein jelly which comprise the spaces between the 

 lipoidal elements of the superficial emulsion. We have seen that 

 permeability is affected by reagents which presumably affect the solu- 

 bility or state of aggregation of the protein constituents of the cell. 

 We should expect, however, to find the permeability of the surface of 

 the cell also affected by lipoid-solvents, especially if these enter into the 

 lipoidal droplets and increase their diameter. 



FIG. 18. Showing successive effects of increasing diameter of the oil-droplets in an 

 emulsion upon the size of the interstitial spaces. As the droplets increase in size until 

 they touch each other the area of the interstitial spaces diminishes. Further increase 

 in the diameter of the oil-droplets increases the sectional area of the interstitial spaces. 



According to the measurements of Osterhout, the various lipoid- 

 solvents, in particular, ether, chloroform, chloral hydrate and alcohol 

 which are also Anesthetics, exert two effects upon protoplasm: The 

 one consists in a decrease of permeability which is reversible, i. e., 

 disappears after removal of the anesthetic. The other effect, which 

 requires large dosages, in an increase of permeability which is found 

 to be irreversible. Since anesthesia is reversible we may presume it to 

 be associated with the former of these effects while the ultimate toxic 

 or lethal effects of these drugs may be referred to the irreversible in- 

 crease of permeability. 



The absorption of these substances by the lipoidal elements of the 

 superficial emulsion with consequent increase in the volume of the 

 lipoidal droplets might lead either to decreased or increased perme- 

 ability for substances which are soluble in water. Provided the lipoidal 

 droplets are not, in the normal superficies of the egg, in physical con- 

 tact with one another, the interstitial spaces between the droplets will 



