DYNAMICS OF MORPHOGENESIS 183 



3°C. and yiir m. at 30°C., i.e., the narcotic effect was greater at 

 the lower temperature. In his experiments Meyer determined 

 merely the minimal concentration that would produce complete 

 narcosis and apparently did not attempt to determine what 

 would occur with higher concentrations. 



My own results with different concentrations are as follows: 

 with concentrations near or somewhat above the narcotic mini- 

 mum (viz., 0.02 m.) the narcotic effect is greater and disinte- 

 gration occurs earlier at the lower (10-1 1°C.) than at the higher 

 temperature (20-2 1°C.) With concentrations considerably higher 

 than this, on the other hand, the temperature relations are just 

 the reverse ; the narcotic effect is greater and disintegration occurs 

 earlier at the higher than at the lower temperature. With these 

 higher concentrations of benzamid the temperature relations are 

 the same as with the higher concentrations of alcohol and KCN 

 and with the lower concentrations they are the same as with 

 the lower concentrations of alcohol and KCN. In spite of the 

 higher coefficient of distribution at the lower temperature, the lower 

 rate of reaction in the organism at this temperature determines with 

 higher concentrations of benzamid a higher resistance than at the 

 higher temperature where the rate of reaction is higher. 



The question at once arises as to how far the coefficient of dis- 

 tribution and how far other factors are concerned in these rela- 

 tions. When low concentrations of alcohol and KCN are used 

 the animals with the higher rate of reaction become more readily 

 and more completely acclimated and so die later than those with 

 the lower rate. But such concentrations of alcohol and KCN are 

 below the minimum which produces complete narcosis. In the 

 case of benzamid the narcotic effect with minimal concentrations 

 is greater at low and less at high temperatures. It is certain 

 that the acclimatization factor is not involved in this primar}^ 

 narcotic effect. There are, however, indications that acclimati- 

 zation to benzamid occurs very rapidly; in sufficiently low con- 

 centrations the animals show signs of recovery from the partial 

 or complete narcosis in less than twenty-four hours at 20°C. 

 In disintegration experiments, therefore the acclimatization fac- 

 tor may play a part as it does with alcohol and KCN, but the 



