io8 



FRANK R. LILLIE. 



reference to the figure and to the description of the operation it 

 will be seen that the line of this fold represents the continuation 

 of the left amniotic rudiment, which was not injured by the 

 operation. 



I conclude, therefore, that when the amniotic rudiment of one 

 side is left free to develop after destruction of the rudiment of 

 the other side just prior to the formation of the head fold, 



FIG. 9. Experiment 57- Under surface of the blastoderm. There is no amnion. 

 The right eye is defective, x marks the location of the secondary amniotic fold 

 shown in Fig. 10. A-B, plane of section shown in Fig. 10. Letters as in Fig. 8. 



the ectamnion is propagated in the normal fashion and induces 

 the formation of a low fold, but that the amniogenous somato- 

 pleure is unable to raise itself around the body of the embryo. 

 The growth of the amniogenous somatopleure appears to be less 

 than normal. 



Amniotic Rudiments of the Right Side. --On the right side, on 

 the other hand, a well-developed fold appears at the place where 

 the extra-embryonic somatopleure becomes continuous with the 



