1+50 



EXPERIMENTAL CHICK EMBRYOLOGY 



If the student has had success with transplantation of limb primordia, he might carry 

 out the following procedure which has as its aim the study of neural crests transplanted 

 from dark to light hreeds of fowl. 



1. Donors consist of any dark breed (e.g., Brown Leghorn, Barred Bock, New Hamp- 

 shire Bed). They should be from 50 to kQ hours incubated (less than 15 somites) 

 at the time of the excision of the neural crest. 



2. Hosts should be about 60 hours incubated. They should be White Leghorns. 



5. Under the usual aseptic conditions, make a longitudinal slit in the chorion, 

 the amnion, and finally at the base of the wing bud. Betum the covered host 

 to the incubator. 



k. With a piece of Nile Blue Stained agar, stain for 10 minutes the head, anterior 

 to the otocyst. 



5. Quickly excise the donor embryo from Its yolk, remove all yolk, and strip a 

 piece of akin from the dorsal and dorso-lateral surface of the head (where it 

 is stained). The neural crest cells will be adherent to the undersurface of 

 this piece of skin. 



6. With pipette and sterile chick Elnger's transfer this neural crest material, to 

 the previously prepared slit at the base of the wing bud of the host. Gently 

 push it deeply into the opening and make certain that it sticks. 



7. Seal the window, iand incubate the egg (without rotation for 1+8 hours) for at 

 least two weeks. If development seems normal, allow some hosts to go to hatch- 

 ing. 



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18 days 



19 days 



20 dais 



21 days 



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DAILY CHANGES IN THE WEIGHT AND THE FORM OF THE DEVELOPING CHICK EMBRYO (WHITE LEGHORN) 



Reprinted by permission of N. Y. State College of Agriculture from Bulletin #205, 

 Bomanoff, 195 1. 



