Life-history of Tetraclinis articulata. 605 
Fig. 50. Two groups of chromosomes and two spindles separating out in the prophase of the 
first sporophyte division, x 530. Sept. 2. 
Fig. 51. The next section from the same series as Fig. 50. x 530. 
Fig. 52. Slightly later stage of the division of the fusion nucleus, x 530. Oct. 3. 
Fig. 53. Later stage of division of the fusion nucleus, x 530. Oct. 3. 
Fig. 54. Binucleate proembryo at the base of the archegonium. x 530. Sept. 23. 
Fig. 55. Four-nucleate proembryo at the base of the archegonium. x 530. Sept. 23. 
Fig. 56. The same stage, but showing the whole archegonium and the ventral canal nucleus, 
x 225. Sept. 23. 
Fig. 57. Various nuclei, unfused, fusing, and fused, from prothallus cells of the same age as 
Figs. 54-6. x 530. 
Fig. 58. Two fusing nuclei in a prothallus cell, x 530. 
PLATE XLVI. (Microphotographs). 
(All x circa 100, except Fig. 60, which is x 250.) 
Fig. 59. Median longitudinal section of young ovule. (Cf. Fig. 31.) 
Fig. 60. Functional megaspore, one of the two abortive spores, and surrounding tapetal tissue. 
(Cf. Fig. 37-) 
Fig. 61. Alveoli, showing the lagging in the development of those at the apex, as compared 
with the others. July 30. 
Fig. 62. Archegonium initials. (Cf. Fig. 39.) 
Fig* 63. Young archegonia, showing very large vacuole filling the greater part of each. 
August 12. 
Fig. 64. Nearly mature archegonia, and end of pollen-tube showing two male cells. (Cf. 
Fig. 41.) 
Fig. 65. Transverse section through an archegonial complex, just below the necks. Note the 
‘asteroids’. Sept. 11. 
Fig. 66. Binucleate proembryo. (Cl. Fig. 54.) 
Fig. 67. Two four-nucleate proembryos in section. (Cf. Figs. 55, 56.) 
