168 



TEXT-BOOK OF EMBRYOLOGY. 



Neural crest 



Myotome -J 



f Cutis plate 

 I Muscle plate 



Pronephros 



I 



Parietal mesoderm — *fc~"V 



\ 



Intestine "-^-i 

 V 



Visceral mesoderm 





Myotome 



Sclerotome 



^-y*" /--"--f-^ * J Upper 



flTT? -g C« c-Iom /#$$£$&!&• /" limb bud 





Amnion 



-"./£"'?- fc;;< /* ,' Umbilical 



&$-Uv'. ° ^', **"'*- «v f > ">*" Vein 



Fig. 142. — Transverse section of human embryo of the 3rd week. 5c/. 1 , Break in myotome at 

 point where sclerotome is closely attached. Kollmann. 



Neural tube 



Intersegmental 

 artery 



Intersegmental { 



artery i 



-■ .'.-' Ectoderm 

 - -1 ^ * 



-fl^"cl- v "' s '- lerotome 



^«» figff £• J - - M yocoel 



4& •?> ■o'i ' 



Fig. 143. — Three primitive segments from sagittal section of human embryo of 

 the 3rd week. Kollmann. 



