234 M. IX AB A. 



is simply that tlie position <jf (hat oro^an is always in the following 

 stages a little removed fr<jni the angle of the mesentery. Further in 

 figs. 1 and 3 the proliferation of the peritoneal epithelium can be 

 roughly se[)arated into two parts, the medial and lateral. 



From the above description, I think that Janosik's statement as 

 to the origin of the cortical cells is quite correct. My figure 1 corres- 

 ponds with his figure 1. The only ditference is that the mesonephros 

 in the mouse is not so well developed as in the case of the pig. 

 Thus Junosik stated that the cells proliferate in the medial direction 

 to the aorta, ^vhich condition is observed in the mouse only on the 

 right side. The mesentery in the mouse being shifted from the 

 medial line a little to the right side, its angle on the left side is 

 carried far to the medial line, so that on this side the suprarenal 

 blastema is projected upwards and a little lateralwards in the direction 

 of the mesonephros (compare figs. 1 and 3). I camiot determine 

 whether the suprarenal body is really the anterior continuation «jf the 

 fj-enerative ridge or not. The state of things as seen in the tigure 

 given by Mihalkovics from a sheep embryo (his fig. 1(37) I could not 

 find at the corresponding point of the mouse. Dut from the fact that 

 the peritoneum is proliferated and tlie su[)rarenal blastema is placed 

 side by side with the generative organ in its entire length, it is more 

 likely to be the lateral separation, and not the anterior continuation 

 of the generative organ. 



Further growth of the suprarenal blastema consists simply in its 

 separation from the peritoneum and clustering into a more compact 

 round mass, as will be seen in fig. 12. The pr<diferation of the 

 peritoneum, though slight, is still observed towards the close of the 

 12th day. Beyond the anterior end of the suprarenal bodies, a slight 

 proliferation of the peritoneum w.is sometimes observed (Fl. XXX. 

 fi^r. 7). I think that the com[)act suprarenal blastema is formed 



