The Early Development of the Pigeon's Egg. 



39 



>- 



r 







^ 



^ 



^ J^ 



Fig. 21. 





Fig. 20. 



Fig. 20. — Surface view of pigeon egg as it appeared at 3.00 a. m., about seven 

 hours after fertilization. 



Fig. 21. — Surface view of pigeon egg obtained at 3.30 a. m., seven and one- 

 half hours after the estimated time of fertilization. 



Fig. 22. — Pigeon egg taken at 2.00 a. m., six hours after the estimated time 

 of fertilization. The same egg is shown in Chart II A. 



