6 4 



H. E. EWING. 



generation was obtained. The means obtained for each subline 

 are here written in parallel rows (the measurements being given 

 in millimeters), the two belonging to the same generation being 

 superimposed : 



Isolations 1.582; 1.909; 1.890; 1.603; I-I35; 1.600. 



Isolation 6 1.640; 1.628; 1.763; 1.488; 1.390; 1.180. 



Here it is observed that two of the six means obtained in the 

 check isolation 6, in which isolation selections were made from 

 the shortest individuals are actually greater than those for the 

 corresponding generations in isolation 5 where selections were 



19 30 31 32 



0.90 



FIG. 3. Plotted curves for check isolations Nos. 5 and 6. In isolation No. 5 

 (curve represented by heavy line) selections were made for increasing the body 

 length. In isolation No. 6 (curve represented by light open line) which was run 

 as a check to S. selections were made for decreasing the body length. Graph 

 made on same plan as in previous figures except that fluctuations of extremes are 

 not given. 



made from the longest individuals. Further, if we plot the 

 curves of the means obtained for the two sublines together (see 

 Fig- 3). we find that they go up and down together and cross at 

 three different points. The fluctuations in size were found to 



