Bui. 844, U. S. Dept. of Agriculture. 



Plate II. 



Fig. I. — Median Section through an Ovule of Melilotus alba. 



The embryo sac is shown ready for fertilization. The egg and synergids are in contact with the 

 outer integument at the micropylar end. The remains of the antipodals mar be seen at the 

 chalazalend. X180. 



Fig. 2. — Section through an Ovule of Melilotus alba, about Three 

 Days After Fertilization. 



The proembrvo, the endosperm, and modifications of the integuments are shown. At this stage 

 the suspens'or is a prominent part of the proembryo, and the endosperm is most abundant around 

 the embryo. The inner integument is being rapidly destroyed, and the outer integument is 

 beginning to form theseed coat, as is indicated by the'modifioations in the outer layer of its cells, 

 which are elongating and thickening their outer walls. X33. 



