76 



H. W. Eand and E. A. Boyden, 



other in size. But the third worm, which was one of the minority 

 in which after the first cut the larg-er eye was inside, showed no 

 such reversal in the relative size of its eyes. The eye which after 

 the first cut was inside and larger came to be the outside eye 

 with reference to the greater curvature caused by the second cut, 

 and it continued to be the larger. Thus the animal which was at 

 first an exception to the rule that outside eyes are larger came, 

 after the second cut, into conformity with that rule. 



III. The behavior of the three worms last referred to led to 

 an attempt to secure more data of the same kind. From seventeen 

 worms the head was removed by an oblique cut as in the experiments 

 already described. At the end of ten days after the operation the 



Fig. E. 



Fig. F. 



Fig. G. 



outside eye was the larger in nine cases, the inside eye was larger 

 in four cases, and in four cases the eyes were equal in size. These 

 seventeen worms were then subjected to a second cutting after 

 the manner described above and illustrated in Figs. E and F. But 

 in this series of experiments the second cutting was not in any case 

 followed by a reversal of the proportions of the two eyes. It is 

 possible that too much time was allowed to intervene between the 

 decapitation and the second operation. The regenerating eyes were 

 perhaps too far advanced in their development to be affected in 

 any marked way by the second cutting. Only further experiment 

 could determine this point. 



