

278 BOTANICAL GAZETTE [april 



structure usual in angiosperms. In E. splendens there are peculiari- 

 ties in the history of the antipodal nuclei which require further 

 study to make definite conclusions possible. It seems probable 

 that each of the 4 antipodal nuclei may undergo a second 

 division. 



7. The obturator arises as an outgrowth of the placenta. It 

 fills the space between the beaklike prolongation of the nucellus, 

 the placenta, and the ovary wall. Its cells disintegrate after the 

 embryo begins its development. 



8. At about the time of the first division of the egg of E. Preslii, 

 endosperm nuclei come to lie between it and the micropylar end of 

 the embryo sac. 



9. The embryo becomes a round mass of cells; this mass 

 elongates and later 2 cotyledons and a well developed root cap are 

 formed. The mature embryo is straight, and, except at the tip 

 of the root cap, is surrounded by the endosperm. In E. Preslii 

 no suspensor was observed; in E. splendens there is a short sus- 

 pensor. 



This paper is the result of work carried on at the University of 



Wisconsin 



my sincere 



University or Chicago 



LITERATURE CITED 



1. Baillon, E. H., Etude general du group des Euphorbiacees. Paris, 1858; 

 rev. in Bull. Soc. Bot. France 5:776-780. 1859. 



2. Brown, R., Miscellaneous works. London. 1866 (vol. I, p. 28). 



3. Capus, G., Anatomie du tissu conducteur. Ann. Sci. Nat. Bot. VI. 7: 209- 

 291. 1878. 



4. Dessiatoff, N., Zur Entwicklung des Embryosacks von Euphorbia 

 virgata. Ber. Deutsch. Bot. Gesells. 29:33-39. 191 1. 



De Candolle, j 

 Hegelmaier (6). 

 Hegelmaier, F.. 



3:71. 1827; cited by 



Gesells 



7- , Zur Kenntnis der Polyembryonie von Euphorbia dulcis. Ber. 



Deutsch. Bot. Gesells. 21:6-19. 1913. 



