ORGANS IN THE EMBRYO OF THE FOWL. I 15 



The embryo is represented in Fig. i 5 as it lies on the reversed 

 blastoderm, the entodermal face of which is up. The allantois 

 is well developed and lies in a special enlargement of the body 

 cavity behind the embryo. 



FIG. 14. Experiment 60, operation diagram. Outline of embryo of chick of about 

 33 hours, after Duval. The ruled area indicates the region of the blastoderm destroyed 

 by the operation. 



In this experiment, as in experiment 57, only the right limb of 

 the ectamnion of the prospective head-fold was destroyed ; and 

 the consequence of this is in both cases the suppression of the 

 amnion with the exception of the tail-fold. In this case the vari- 

 ous membranes have been so confused by the curious position of 

 the embryo and by various secondary fusions that it is quite 

 impossible to determine the behavior of the uninjured rudiment 

 of the amnion of the left side. A single section may serve to 

 illustrate one of the very peculiar conditions (Fig. 16). Lying 

 above the embryo is seen the blastoderm composed of the 

 somatopleure and splanchnopleure. The body-wall of the 

 embryo has fused with the splanchnopleure in such a way that 

 the two are directly continuous on both sides, and the body wall 

 may be traced directly into the wall of the intestine. The result 



