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PROFESSOR W. WILLIAMSON ON THE ORGANIZATION 
Fig. 52. Spore like figs. 44 and 47, but exhibiting the cell, d , of fig. 46 crossing the 
disk of the spore at d'. 
Fig. 53. Transverse section of the Lepidostrobus, from which the spores, figs. 39 
to 47 were derived, a. Vascular axis displaced, b. Prosenchymatous 
cells of the outer cortical layer, c, c , c". Sporangiophores. d. Sporangia 
with spores in groups of 4, and mother or sister cells, e. Sporangium 
walls. Enlarged 12 diameters. 
Fig. 54. Slightly oblique tangential section of the same Lepidostrobus as fig. 53, 
made nearly in the plane of the outer surface of the vascular axis of the 
strobilus. Enlarged 5 diameters. 
Fig. 55. Oblique tangential section of the same made a little external to fig. 54. 
Enlarged 4 diameters. 
Fig. 56. Longitudinal section of a portion of the same. Enlarged 14 diameters. 
Fig. 57. A single sporangium of the same Lepidostrobus, with numerous clusters of 
tetraspores and sister (?) cells. Enlarged 50 diameters. 
PLATE 23. 
Figs. 58, 59 and 60. Macrospores from Halifax. Enlarged 43 diameters. 
Figs. 61 and 62. Similar macrospores. Enlarged 100 diameters. 
Fig. 63. Similar macrospore, but with numerous unbranched peripheral appendages. 
Enlarged 214 diameters. 
Fig. 64. Three macrospores enclosed within their sporangium. Enlarged 50 diameters. 
Fig. 6 4 A Peduncular appendage like those ( d and e) of the two lower macrospores 
of fig. 64, and at d, e, in figs. 65 and 66. Enlarged 40 diameters. 
Figs. 65-66. Two macrospores containing endospermic cells. Enlarged 43 diameters. 
Fig. 66 a. Macrospore containing endospermic cells of uniform size. Enlarged 33 
diameters. 
Fig. 66 b. Similar macrospore to fig. 66 a, but with the endospermic cells of various 
sizes. Enlarged 33 diameters. 
Fig. 66c. Macrospore filled with parenchymatous cells. 
Fig. 67. Transverse section of a remarkable conceptacle. Enlarged 50 diameters. 
Fig. 68. Segment of the peripheral wall of fig. 67. Enlarged 214 diameters. 
Fig. 69. A crushed specimen of the same conceptacle. 
Fig. 69 a. Another specimen of the same conceptacle, in which the central structure, 
6 7, d, is seen to be occupied by a mass of parenchymatous cells. Enlarged 
66 diameters. 
Fig. 70. Two peripheral appendages from a macrospore like figs. 58-66, apparently 
consisting of two layers of tissue. 
Fig. 71. A macrospore with unbranched peripheral appendages. Enlarged 100 
diameters. 
