The Early Development of the Pigeon's Egg. 41 



und kleinercn KngX'ln der einen Hiilfte der Keimscheibe angehoren 

 und der Mittelpunkt des Feldes mit Eurchnngskugeln excentrisch 

 liegt." (Kollikcr ('7G), p. Y9.) 



Fig. 26. — Pigeon egg six and one-Iialf hours after tlie estimated time of 

 fertilization, 2.30 a. m. 



Fig. 27. — .Surface view of a pigeon egg at 3.15 a. m., about seven and.one- 

 fourtli liours after fertilization. Compare witli Figs. 28, 20 and 30. Tlie 

 numbers suggest homologies in cells, but have no reference to order of cleavage. 



The EigJd-celled and Later Stages. — Eggs in approximately the 

 eight-celled stage are shown in Figs. 27 to 37. There is here quite 

 a variety in the cleavage pattern. Fig. 27 lacks only one plane 



