18 BOTANICAL GAZETTE [yuLY | 
Fic. e Division of antheridium initial. x 1500. 
Fic. 20. Two prothallial cells, primary spermatogenous cell, tush tube | 
nucleus. . 1500 
Fic. 2 “oT eleion of primary spermatogenous cell. X 1500 
Fic. 22. The two prothallial cells, stalk cell, body cell, ai tube nucleus. 
X 1500 
showing the two integuments and nucellus with gametophyte. * 46 
Fic. 24. Section through the strobilus above the nucellus showing the four 
parts of the outer integument and the two parts of the inner integument which 
later become tubes. X 46. 
1G. 25. Section through the strobilus at level of gametophyte, showing the 
46. 
1G. 26. Megaspore mother-cell becoming differentiated. x 500. 
Fic. 27. Megaspore mother-cell, resting stage. 500. 
Fic. 28. Megaspore mother-cell dividing. X 500. 
1G. 29. A row of four megaspores, showing late division of upper daughter 
500. 
1G. 30. A row of three megaspores; the upper daughter-nucleus has failed 
to divide. X 500 
FIG. 31. First division of the megaspore, showing formation of the central 
vacuole. X 500 
Fic. 32. ious celled stage of female gametophyte. x 5 
Fic. 33. Simultaneous division of the nuclei; eight- celled stage. X 500. 
Fic. 34. Female gametophyte; sixteen cells. x 500 
Fic. 35. Female gametophyte; simultaneous dividion to form sixty-four free , 
nuclei. X 500 
Fic. 36. Archegonium with primary neck cell and central cell. x 500. 
Fic. 37. Archegonium showing the enlarged central cell and two neck cells. 
X 500. 
Fic. 38. Transverse section of gametophyte at level of central cell, showing 
a large, a small, and an abortive archegonium. x 75. 
Fic. 39. Transverse section through neck of an archegonium at a distance 
of 40 above the central cell. x 500. 
Fic. 40. An archegonium slightly older than fig. 37. X 500 
Fic. 41. Two archegonia just before the division of the nucleus of the central 
Fic. 42. Egg nucleus and ventral nucleus lying in the upper part of the 
archegonium. XX 500 
Fic. 43. Egg ‘yt near the center of archegonium and surrounded by a 
pares of thickened cytoplasm, and ready for fertilization. x 500. 
Fic. 44. Longitudinal median section through the ovule and integuments, 
showing reproductive, storage, and haustorial regions of the gametophyte x 48. 
Fic. 23. Median longitudinal section through a megasporangiate strobilus ea 
