1 7 4 BOTANICAL GAZETTE [march 



Fig. 38. By successive divisions of primary neck cell and growth of central 

 cell, a characteristic archegonial projection is formed; cytoplasm of central cell 

 with peculiar thread structures. 



Fig. 39. Nucleus of central cell in early prophase; spirem continuous; a 

 single nucleolus. 



Fig. 40. Early metaphase; chromosomes, daughter halves in pairs, have 

 shortened. 



Fig. 41. Anaphase; cell growth continuing during mitosis. 



Fig. 41a. Same mitotic figure shown in fig. 41 under higher magnification; 

 two sets of daughter chromosomes almost similar in amount; thread structures 

 in cytoplasm. 



Fig. 42. Telophase; two daughter nuclei unequal in size; ventral nucleus 

 considerably larger than nucleus of neck canal cell. 



Fig. 43. Prophase of mitosis in a neck canal cell. 



Fig. 44. Anaphase of same. 



Fig. 45. Telophase; a cell plate laid down between two neck canal cell nuclei; 

 cytoplasm with vacuoles of various sizes. 



Fig. 46. Section of archegonium after formation of two neck canal cells; 

 the two nuclei in contact, the cell plate having already disappeared; nucleus in 

 ventral cell in metaphase. 



Fig. 46a. Nucleus of ventral canal cell shown in fig. 46 under higher magni- 

 fication; deeply staining body near spindle. 



Fig. 47. Section of archegonium; ventral cell nucleus in telophase; two 

 nuclei of neck canal cell in contact. 



Fig. 470. Two daughter nuclei shown in fig. 47 under higher magnification; 

 size and shape quite different; both contain a number of nucleoli; dome-shaped 

 cell plate laid down separating egg and ventral canal cell. 



Fig. 48. Section of archegonium after completion of egg, ventral canal 

 cell, and neck canal cells; nucleus of egg larger than others. 



Fig. 49. Section of archegonium with open neck ; canal cells becoming muci- 

 laginous, with disorganizing nuclei; egg nucleus irregular; single nucleolus 

 present, due to union of several nucleoli seen when nucleus was organized. 



PLATE VIII 



Fertilization 



Fig. 50. Entrance of a number of sperms; many of them have already reached 

 the egg. 



Fig. 51. Union of sperm and egg; sperm partly within egg nucleus; cytoplasm 

 of egg enveloping nucleus very shallow toward neck. 



Figs. 52a, b. Two sections of same egg nucleus containing sperm, which 

 has not changed; clear region surrounding sperm; upper side of figures toward 

 neck. 



Figs. 53a, b. Two sections of same egg nucleus containing sperm in later 

 stage than that shown in previous figures; disintegration begun; compact body 



