234 



ALBERT KUNTZ 



suprarenals, such cells have descended as far as the mesial sur- 

 faces of these bodies which, at this time, appear as compact cell- 

 columns more or less circular in transverse section, lying parallel 

 with the aorta a short distance from its ventro-lateral surfaces 

 (fig. 11, supr.). Posterior to the suprarenals, small cell-aggre- 

 gates are present all along the ventro-lateral surfaces of the aorta 

 as far as the origin of the iliac arteries. It is impossible, in this 

 stage, to determine the limits of the anlagen of the several sym- 





CMi/i/- 



4*I» 





msm 



\mp\c 



<ines. 



Fig. 11. Transverse section through the sympathetic trunks and the supra- 

 renal bodies of an embryo 9 mm. in length, X 150. 



pathetic plexuses in this region. The only distinction between 

 the cell-aggregates which constitute the anlagen of the cceliac, 

 the renal, the abdominal aortic, and the hypogastric plexuses 

 consists in a difference in degree of development. Development 

 proceeds somewhat more rapidly in the anterior than in the pos- 

 terior region. In transverse sections through this region, traces 

 of one or the other of these plexuses appear in nearly every sec- 

 tion. 



