

Seaton : Embryo-sac of Nymphaea advena 289 



10. The large fusion-nucleus lies in the narrow part of the 



embry 



When 



across the embryo-sac as Cook found in his material. 



12. The scanty cytoplasm of the embryo-sac gathers around 

 the fertilized egg in a characteristic manner. 



13. The fusion-nucleus may divide at the time of fertilization 

 of the egg but usually this occurs later. 



14. The lower endosperm-nucleus, arising from the division 

 of the fusion-nucleus, travels to the chalazal end of the tube-like 



part of the sac and persists until the embryo has attained consider- 

 able size. 



15. The embryo is spherical, lying against the wall, almost 

 surrounded by endosperm, within the perisperm, rich in food. 



16. The Nymphaeaceae are monocotyledonous in embryology, 

 vascular tissue, habit, and possibly even in floral arrangement. 



Conard, H. S. 



Literature 



Ny 



Cook, M. T. 



e Institution of Washington, Publication no. 4. 1905. 



Development of the embryo-sac and embryos of Castalia 

 Nymphaea advena. Bull. Torrey Club 29 : 211-220. 



PL 12, 13. i 902 



^yon, H. L. Observations on the embryogeny of Nelumbo. Minn. 

 B ot. Stud. 2 : 643-655. //. 48-50. 1 901. 



Schaffner, J. H. Some morphological peculiarities of the Nym- 

 phaeaceae and Helobiae. Ohio Nat. 4 : 83-92. //. 5-7. i9°4- 



Cornell University, 

 Ithaca, New York. 



