WOUND HEALING IN EMBRYOS 



237 



In an injured egg the edges of the coat at first re- 

 tract, then contract. Vital dye marks are dragged 

 out centripetally . 



A wound inflicted within the unsegraented area pulls 

 into its orbit nelg)ibouring cells by the expansion 

 of the syncytial coat. 



T}ie contraction of an epitlielial wound orients the 

 adjacent cells like the petals of a daisy. 



(Illustrations from Holtfreter: 19^5- Jour. Exp. Zool. 93:251) 



