IOS E. G. SPAULDING. 



The chemical changes in the solute to which they are due may 

 in turn be accompanied by electrolytic phenomena, and so by an 

 attraction of unlike and repulsion of like charges, so that with 

 all of these factors taken together reasonable grounds are fur- 

 nished for the understanding of the presence of irregularities in 

 the cleavage form. The fact of this constricted form and of the 

 possibility of its explanation on the above basis must be con- 

 stantly kept in mind in the subsequent considerations. If then 

 the final event in the series of changes leading up to segmenta- 

 tion is that ending with a change of form and average decrease 

 and rearrangement of surface tension, after which a " resting 

 stage" of relative equilibrium exists for at least some time, then 

 this series of events must have resulted from or be in part iden- 

 tical with a disturbance of equilibrium within the cell before the 

 event of cleavage. The various theoretically possible ways in 

 which this disturbance can be brought about must therefore be 

 presented systematically and in detail. 



5. POSSIBLE WAYS OF CREATING A DIFFERENCE BETWEEN THE 

 TWO POTENTIALS CONCERNED, PRESSURE AND TENSION. 



There is, first, the possibility that the surface tension may 

 be greater than the osmotic pressure of the moment can with- 

 stand, /'. e., that a potential difference in the direction of surface 

 tension osmotic pressure has been formed. This of course is 

 equalized with the establishment of equilibrium, but therewith 

 both extensity factors, surface and volume must have decreased 

 and the cell have lost water, while both intensities, tension and 

 pressure, however, have presented an absolute increase. A po- 

 tential difference in this direction might theoretically be caused in 

 two ways, either (i) by increasing the surface tension or (2) by 

 decreasing the osmotic pressure, in each case keeping the other 

 potential constant. Conversely, if the osmotic pressure is first 

 increased, e. ., by an analytic chemical process resulting from 

 oxidation, or if the surface tension is first decreased by, e. g., 

 electrical charges, then a potential difference in the direction of 

 osmotic pressure --surface tension will exist. This being un- 

 compensated, the resulting process of equilibrating is identical 

 with the taking place of an increase in both extensity factors and 



