I5O RALPH S. LILLIE. 



10-15 per cent., 25-30 per cent., 40-50 per cent., and 50-60 

 per cent. ; compare (e. g.) the proportion of corpuscles haemolyzed 

 by .00227 n NHs in 10, 15, 18 and 23 minutes, viz., respectively 

 10, 20, 30, and 40 per cent. The influence of temperature upon 

 the rates of the two processes is also of the same general kind, 

 although certain differences are seen; in both cases the average 

 value of the temperature-coefficients is greater than that of 

 typical chemical reaction-velocities; but in haemolysis the vari- 

 ability of the coefficient with change of temperature is less, and 

 its value decreases with increase in the effective time of action. 2 

 The agreements, however, are sufficiently close to indicate that 

 the same kind of process lies at the basis of both effects, con- 

 sisting apparently in the progressive combination of the acid or 

 base with some cell-constituent until a certain critical quantity 

 or local concentration of reaction-product is formed. Arrhenius 







also infers a chemical binding of the haemolyzing acid or base to 

 some substance in the erythrocytes. 



In general we may conclude that in both cytolysis and the 

 activation of the egg-cell the characteristic effect depends pri- 

 marily upon the formation and accumulation of a reaction- 

 product whose presence is the cause or condition of some definite 

 physical change of state or structural alteration in the cell-system, 

 especially in the surface-layer. In the egg-cell the structural 

 conditions under which the normal metabolic reactions take 

 place are modified, and the course of metabolism is changed; 

 development then proceeds. In either type of cell, if an insuf- 

 ficient quantity of the activating substance is formed as by too 

 brief exposure the effect is incomplete or fails to appear; thus in 

 order to liberate haemoglobin from erythrocytes by means of a 

 given solution of ammonia at a constant temperature, a certain 

 minimal time of exposure is required; with briefer exposures no 

 visible effect is produced. We have seen that in the starfish egg 

 exposures briefer than the optimum may produce visible effects 

 (membrane-formation, imperfect cleavage, etc.) indicating a 

 partial degree of activation; in the case of haemolysis it is also 

 to be assumed that brief exposures cause a partial cytolytic 

 effect, which however is insufficient to liberate haemoglobin and 



" Immunochemistry," pp. 107 seq.; "Quantitative Laws," pp. 65 seq. 



