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Early Development of the Hen's Egg. 



127 



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11 



Fig. 11. — A section through line A — B of Fig. 10. vi.p., marginal periblast ; 

 c.n., cleavage nucleus; /, neck of the latebra. X 52. 



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13 



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Fig. 12.— The four-celled stage, drawn from a whole mount preparation. 

 The egg as taken from the isthmus (see Table 1, hen No. 3). a.c, acces- 

 sory cleavage furrows. X 18. 



Fig. 13.— An eight-celled stage, drawn from a whole mount preparation. 

 The history of this egg is given in Table 1, hen No. 4. It shows one central 

 and seven marginal cells, a.c, accessory cleavage furrows ; s.a.c, small acces- 

 sory cleavage cells. X 18. 



