io6 BOTANICAL GAZETTE [august 



2. The vertical walls in each tier are formed by the secondary 

 fibers from the nuclei of their respective tiers. 



3. The first cross walls and the first vertical walls are formed 

 in connection with the division of the first four free nuclei at the base 

 of the egg. 



4. The second division in the basal end of the egg may take place in 

 either tier. 



5. In the last division the four nuclei do not always divide simul- 

 taneously. 



The University of Chicago 



LITERATURE CITED 



1. HoFMEiSTER, W.^ On the germination, development, and fructification of the 



higher Cryptogamia and on the fructification of the Coniferae (English 

 translation). London. 1862. 



2. Strasburger, E., Ueber Zellbildung und Zelltheilung. Leipzig. 1878. 



3. Blackman, V. H., On the cytological features of fertilization and related 



features in Pimts silvestris L. Phil. Trans. Roy. Soc. London B. 190: 

 395-426. pis. 12-14, 1898. 



4. Chamberlain, C. J., Oogenesis in Finns Laricio, Box, Gazette 27:268-280. 



pis, 4-6, 1899. 



5. Ferguson, Margaret C, Contribution to the knowledge of the life-history 



of Pinus. Proc. Wash. Acad. Sci. 6:1-202. pis, 2-24. 1904. 



6. MiYAKE, K., On the development of the sexual organs and fertilization in 



Picea excelsa. Annals of Botany 17:351-372. pis. 16-1^, 1903- 



EXPLANATION OF PLATES VIII AND IX 



PLATE VI U 



Fig. I. Section showing fibers between nuclei that give appearance of verti- 



cal wall. X225. 



disappe 



blunt broad spindles, and coarse granular substance. x6io. 



Fig. 3. Telophase of same division; fibers radiating in all directions; cell 

 plate not yet visible. X35S. 



Fig. 4. Appearance of cell plate; nuclear membranes; dark areas above 

 daughter nuclei; fillers radiating from nuclei and coarse granules strung along 

 fibers; secondary fibers coming together in the center, upon which is formed the 

 vertical wall. X390. 



Fig. 5. Later stage in cross walls and beginning of vertical walls. X365. 

 Fig. 6. Later stage in formation of vertical walls; fibers radiating from 

 nuclei. X390. 



