222 BOTANICAL GAZETTE [SEPTEMBER 
Fic. 22. Anastomosing pollen tubes. X 200. 
Fic. 23. Megaspore mother cell showing nucellus and first integument. 
Fic. 24. Later stage of megaspore. 1260. 
Fic. 25. Binucleate stage of the embryo sac. 1260. 
Fic. 26. Normal four-nucleate stage of embryo sac. 00. 
Fic. 27. Frequent form of the four-nucleate stage of embryo sac; also a third 
X 400. 
: 28. Mitosis of the four-nucleate sac. goo. 
Fic. 29. Eight-nucleate sac; unusual mitosis in antipodal end. X 1200. 
Fic. 30. Usual eight-nucleate sac with the egg apparatus organizing and the 
polars approaching each others preparatory to fusion. goo 
Fic. 31. Embryo sac showing more than eight nuclei, but no sign of polarity. 
x 
Fr IG. 32. Multinucleate embryo sac showing polarity. goo 
Fic. 33. Eight-nucleate sac showing fusion of polars and entrance of pollen 
tube bearing the two male cells. x 1450. 
__ Fic. 34. Embryo sac showing one male cell in the act of fusing with the fusion 
nucleus, and the other near egg. 1450. 
Fic. 35. First integuments; nucellus showing beak and bearing pollen tube; 
embryo sac showing first division of fertilized egg and multinucleolate nuclei of 
endosperm. X 500. 
Fic. 36. Embryo sac showing two-celled embryo unusually large; multi- 
og nuclei of rapidly forming endosperm; also an antipodal egg. *8r0. 
G. 37. Embryo sac showing two-celled embryo, and the beginning of the 
Lente: of endosperm tissue. X 1200. 
Fic. 38. Ordinary type of two-celled embryo. 500. 
Fic. 39. Three-celled embryo. X 500. 
Fic. 40. Four-celled embryo showing first vertical wall. 500 
Fic. qr. F — embryo showing usual method of formation of second 
vertical wall. 
Fic. 42. ae ae embryo; both end cells dividing at once. * 50° 
Fic. 43. Three-celled embryo showing second cell dividing before the 
cell. 500 
Fie. 44. F acialous form of embryo. X 500. 
Fic. 45. Anomalous form of embryo. 500 
end 
Fic. 46. Later embryo showing the periblem in the cotyledonary region; also 
mitosis in the hypocotyledonary region. x 4oo. 
Fic. 47. Embryo showing periblem in EELS: region. d 
Fie. 48. Advanced ees showing early development of veriblem see 
dermatogen of root tip. x 
Fic. 49. Two embryos in Bie micropylar end of sac. X 500. oak 
Fic. 50. Well-formed embryo in micropylar end of sac; endosperm in 
taneous mitosis; egg-like formation in chalazal end. X 400. 
