DYNAMICS OF MORPHOGENESIS 



175 



These differences in resistance occurring at temperatures only 

 10° apart are certainl}^ far greater than we should expect as the 

 result of a change in the coefficient of distribution. With an 

 increase of 10° the coefficient of distribution would increase less 

 than one-third, if its increase is uniform. If this factor alone 

 were concerned, the difference in resistance of the worms at 10° 

 and at 20° would be slight. 



Series 562 below gives results obtained with a temperature 

 interval of only 5°C. Here young worms with a higher rate of 

 reaction were used and also a higher concentration of alcohol, so 

 that all times are shorter than in the preceding series. 



Series 562. Worms 7 mm. in length from the same stock. Lot 

 1, ten w^orms in alcohol 6 per cent at 20°C. Lot 2, ten worms in 

 alcohol 6 per cent at 15°C. Worms in alcohol 2.30 p.m., October 

 29, 1912. Observations every half-hour, table 4. 



TABLE 4 



