Fertilization in Pinus Strobus. 479 
Fig. 81. A portion of the lower part of an oosphere after the formation of the 
eight nuclei of the proembryo, x 70. 
Fig. 81 b. A part of the above giving details. No cell-walls have as yet been 
formed, x 540. 
Fig. 82. A somewhat later stage than number 81. x 70. 
Fig. 82 b. A portion of the above, showing cell-walls in the process of formation, 
x 540. 
Figs. 83-84. Some of the aspects presented by the ventral canal- cell, x 540. 
Figs. 85-86. Figures occurring in the upper part of archegonia during the 
division of the segmentation-nuclei, x 540. 
Figs. 87-87 b. Figures occurring in the upper part of an archegonium at the time 
of the second division following fertilization : Fig. 87 represents the vegetative 
nucleus, and the karyokinetic structure in Fig. 87 b the smaller sperm-nucleus ; just 
above this figure is tbfe stalk-cell, x 540. 
Cornell University. 
Oct. 1, 1900. 
