494 BOTANICAL GAZETTE [December 



Fig. 25. — Similar stage to fig. 24, excepting the presence of centrosome- 

 like structures at the poles. 



Fig. 26. — Nucleus in the lower cell in anaphase; nucleus in the upper cell 

 in resting condition. 



Fig. 27. — Metaphase of the nucleus in the upper cell of 2-celled stage; the 

 lower cell is not drawn. 



Fig. 28. — Late metaphase of the nucleus in the upper cell; nucleus in the 

 lower 'cell in resting condition. 



Fig. 29. — Telophase of nucleus of the upper cell; a new cell wall is being 

 laid down between two daughter nuclei. 



Fig. 30. — Male gametangium of 3 cells: the nuclei in the upper two cells 

 are in resting condition; the nucleus in the basal cell in prophase, showing 

 24 chromosomes and a nucleolus. 



Fig. 31. — Male gametangium of 3 cells: the nucleus in the terminal cell 

 is in metaphase; centrosome-like structures at the poles of the spindle. 



Fig. 32. — Male gametangium of 3 cells: the nucleus in the terminal cell in 

 metaphase, with centrosome-like structures at the poles; the nucleus in the 

 middle cell in anaphase, and that of the basal cell in resting stage. 



Fig. 33. — Male gametangium of 4 cells: the nucleus in the terminal cell is 

 in metaphase; that of the middle cell in prophase, showing 24 chromosomes. 



Fig. 34. — Male gametangium of 4 cells: two nuclei are in prophase; 24 

 chromosomes are clearly present; one in anaphase and the other in resting 

 condition. 



Figs. 35, 36. — Mitotic figures of the nucleus in a vegetative filament: 

 fig. 35, anaphase; fig. 36, prophase, showing 24 chromosomes. 



Figs. 37, 38. — Cross-section of a male gametangium of 5 cells: fig. 37, 

 metaphase of the mitosis which divides the filament into two rows of cells; 

 fig. 38, prophase of the same, showing 24 chromosomes. 



Fig. 39. — Tip of a vegetative filament, showing stages in the formation of 

 male gametangia; the male gametangia have arisen from the third, fourth, 

 sixth, and seventh cells; four nuclei in the three young gametangia are in 

 prophase; 24 chromosomes can be counted in each. 



Fig. 40. — Portion of a male gametangium of 2 rows of cells: one nucleus in 

 metaphase, one in prophase showing 24 chromosomes, and three others in 

 the resting condition. 



Fig. 41. — Portion of a more advanced male gametangium: four nuclei 

 in prophase, clearly showing the 24 chromosomes. 



Fig. 42. — Cross-section of a male gametangium at about the same stage 

 as in fig. 41 ; one nucleus is in prophase; 24 chromosomes present. 



Fig. 43. — Portion of a male gametangium at about the same stage as in 

 fig. 41 ; two nuclei are in anaphase. 



Fig. 44. — Cross-section of a male gametangium at about the same stage 

 as in fig. 43 : two nuclei in prophase of the mitosis which divides the filament 

 into a structure with four rows of cells. 



