33. EXTIRPATION EXPERIMENTS 

 ON ORGAN ANLAGEN 



PURPOSE: To remove organ anlagen and to determine the ability of the embryo to adjust 

 to the loss. 



MATERIALS: 



Biological: Various stages of Amblystoma as designated for each experiment. 



Technical: Standard equipment for operating on and caring for embryos. 



METHOD: 



Precautions : 



1. The post operative care of embryos is important, for they are naturally sus- 

 ceptible to bacterial infection. This can be reduced somewhat by operating 

 and healing in 0. 1% sodium sulphadiazine, and keeping them in cool media. 



2. Remove only the areas and cell layers indicated, at the designated stage. 

 Organ fields become contracted with succeeding stages. 



3. Study section on "Wound Healing", p. 242. 



Controls : The controls for extirpation experiments consist of the same operation but 

 without the actual removal of the organ anlage. 



Procedure : Operate in 10% Standard Solution and transfer to full strength Standard 

 Solution when the wound is fully healed. 



.TAIL BUD 



SOMITES 



NEURAL TUBE 



PRONEPHROS ;EAR 



ORGAN FIELDS 



RANA PIPIENS 



STAGE 16 

 CLOSED NEURAL. TUBE 



FORE LIMB 



GILL 



EYE' 

 LENS 

 NOSE 



HYPOPHYSIS 



AMBLYSTOMA 

 PUNCTATUM 



STAGE 31 



250 



HYPOPHYSIS 



