n6 



FRANK R. LII.LIE. 



of this fusion must have been an opening on each side into the 

 yolk-sac ; but this has been roofed over by extension of the 



B 



FIG. 15. Experiment 60. Under i.e. entodermal, surface of the blastoderm. 

 The embryo is anamniote, but otherwise quite perfect, all, allantois ; e.b.c., extra- 

 embryonic body-cavity ; vitelline arteries and veins shown A-, plane of the sec- 

 tion shown in Fig. 1 6. The embryo was suspended within the yolk-sac, as described 

 in the text. 



blastoderm surrounding it. Farther back the wall of the intes- 

 tine becomes continuous with the extra-embryonic splanchno- 

 pleure. 



In the region of the tail rudiments of the tail -fold of the 

 amnion are found. 



Two other completely anamniotic embryos (numbers 1 12 and 

 124) were produced by experiments similar to those already 

 described. Both of these had passed through the hole made in 

 the blastoderm and were suspended within the yolk-sac. One of 

 these was much farther developed than number 60. They confirm 

 the general results of the dependence of amnion formation on the 

 presence of the head-fold. They possess other definite lesions, 

 the effects of which will be described in another paper. 



