286 LIMB F lELD OPERATIONS 



Spalteholtz preparations of llmta and entire larvae should be made. Then, make the follow- 

 ing cuts on appropriate larvae and study the regeneration potencies. 



a. Cut off the right forelimh at the level of the wrist. 



b. Cut off the right forelimb halfway between the wrist and girdle, above the bend 

 of the elbow. 



c. Eepeat "a" and "b" but make the cuts at the greatest possible angles. 



d. I4ake transverse cuts at the levels of "a" and "b" but extend the cut only half- 

 way through the limb (or wrist), leaving all parts attached. 



In each case, make a sketch of the limb and the extent of the cut. When regeneration 

 is complete, dissect out the parts to demonstrate the details of regeneration or clear the 

 larva by the Spalteholtz method. This method will show cartilage and bone development but 

 little information relative to nerve and muscle regeneration. 



BECORD OF LIMB REGENERATION EXPERIMENTS 



OBSERVATIONS AND TABULATION OF DATA : 



Drawings, photographs, and preserved specimens constitute the record of the above ex- 

 periments on the limb field. It is most important that detailed records be kept, particu- 

 larly regarding the age and stage of the donor and of the host, the ex\;ent (a-eal and 

 depth) of transplants, the angles of cuts, etc. Confirmatory histological analysis is ex- 

 cellent but Is not always necessary. It is more Important that the student carries out 

 thoroughly one of the above procedures rather than to attempt parts of the entire exercise. 



