Text-fig. IX. Embryo sac of Trapa. i. Embryo sac mother-cell; nucleus in synapsis. 2. The same; heterotype 
division. 3. Tetrad; lower megaspore growing. 4. Chalazal megaspore in binucleate stage. 5. Upper part of mature sac, 
with egg apparatus obliquely cut. 6 a , b. Two succeeding sections through antipodal region; antipodal nuclei deforming. 
1-4. Trapa natans var. incisa , x 600. 5, 6. T. natans, x 860. 
