1912] YAMANOUCHI—CUTLERIA 495 



Fig. 45. — Portion of a male gametangium consisting of 4 rows of cells: 

 one nucleus is in anaphase. - 



Fig. 46. — Portion of a male gametangium at about the same stage as in 

 fig. 45: one nucleus is in prophase, showing clearly 24 chromosomes. 



Figs. 47, 48. — Portion of a male gametangium at a more advanced stage: 

 one nucleus in fig. 47 in prophase, showing 24 chromosomes; one nucleus both 

 in figs. 47 and 48 in metaphase; and two nuclei in fig. 48 in anaphase. 



Fig. 49. — Portion of a male gametangium, showing the last division of 

 nuclei; one nucleus is in prophase and the other in metaphase. 



Fig. 50. — Cross-section of a male gametangium at about the same stage 

 as in fig. 49; one nucleus is in prophase, two others in metaphase of the mitosis 

 which divides the filament into a structure of 8 rows of cells. 



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Fig. 51. — Cross-section of a mature male gametangium: nuclei are in rest- 

 ing condition. 



Fig. 52. — Cross-section of a mature male gametangium, showing the 

 plastids that are associated with the red pigment. 



PLATE XXVII 



The formation of the female gametangium of Cutleria multifida 



Fig. 53. — Portion of thallus of a female plant, showing a single layer of 

 superficial cells and the larger cells below; one of the superficial cells has in- 

 creased in size, and will be the female gametangium later. 



Fig. 54. — One of the superficial cells becomes still larger in size: nucleus 

 is in prophase; 24 chromosomes and a nucleolus are present. 



Fig. 55. — Nucleus in metaphase; centrosome-like structures at the poles 

 of spindle. 



Fig. 56. — Anaphase. 



Fig. 57. — Later telophase: cell wall is being laid down between the newly 

 formed daughter nuclei. 



Fig. 58. — Female gametangium of 2 cells. 



Fig. 59. — Nucleus of the upper cell in prophase; nucleus of the basal cell 

 in resting condition. 



Fig. 60. — Nucleus of upper cell in metaphase. 



Fig. 61. — Nucleus of upper cell in anaphase. 



Fig. 62. — Late telophase of nucleus in upper cell. 



Fig. 63.— Female gametangium consisting of 2 cells: nucleus of basal 

 cell in metaphase. 



Fig. 64. — Nucleus in basal cell in anaphase. 



Fig. 65.— Female gametangium of 3 cells: nucleus of basal cell in prophase; 

 24 chromosomes and a nucleolus are present. 



Fig. 66.— Nucleus of terminal cell in prophase, showing 24 chromosomes; 

 nucleus of basal cell in metaphase. 



Fig. 67. — Nucleus of terminal cell in metaphase. 



Fig. 68. — Nucleus of terminal cell in anaphase. 



