422 



H. H. Newman and J. T. Patterson. 



FIG. 23. A section taken through the belly-stalk near the posterior tip of the al- 

 lantoic entoderm (al. en.}. The mesoderm is indistinctly divided into two por- 

 tions: (1) that forming the belly-stalk bands, and (2) that part immediately sur- 

 rounding the allantoic tube this may be called the allantoic mesoderm (al.ms.}. 

 The belly stalk is here separated from the wall of the yolk-sac by a space (ex.c .), 

 which is only a part of the general extra-embryonic cavity. X 143. 



