554 EDMUND NEWTON HARVEY 



to the surface layer only. This would explain the relatively small 

 amount of alkali which Barratt found to be taken up. 



The change thus brought about in the cell surface alters its 

 properties in three conceivable directions, — surface tension, elec- 

 trical polarization and permeability. The alteration in the latter 

 property is in the direction of an increase in permeability, since 

 finally the surface becomes so altered as to allow the inorganic 

 alkali itself to pass. 



In Paramoecium, cytolysis, in Elodea, rotation, and in the sea 

 urchin egg, irregular fragmentation and division result before any 

 appreciable amount of NaOH has entered. We must consider 

 then, that all these changes are essentially an expression of some 

 profound alteration in the cell surface, involving one or all of the 

 properties mentioned above. 



In recent years more and more stress has been laid on the im- 

 portance of a surface layer differing markedly from the interior of 

 the cell and the role played by surface energy in cell dynamics. 

 It seems that we cannot attribute too much functional value to 

 this barrier or passageway between cell and environment, the 

 'Umwelt und Innenwelt.' Life has been defined as ''the con- 

 tinuous adjustment of internal relations to external relations." 

 Should we not, therefore, look to the boundary between the two 

 'worlds' for an explanation of many of the phenomena exhibiting 

 such unusual charact'eristics as to receive the special designation 

 — vital? 



SUMMARY OF RESULTS 



1. The basic dyes fail to enter cells in the acid condition, i.e., 

 as the dye salt. Certain acid dyes do enter in the acid condition 

 but not in neutral or alkaline solution. The latter combine with 

 the nucleus and protoplasm leading to death of the cell; the former 

 (in the concentrations used) with non-essential elements. In 

 animal cells, these elements are granules which may be distin- 

 guished by their specific gravity. As a general rule they are the 

 heaviest substances present, as determined by the centrifuge. 



