166 BOTANICAL GAZETTE [august 



Fig. 13. — Embryo sac mature and in contact with inner integument; 

 X920. 



Fig. 14. — Egg apparatus with synergids showing filiform apparatus; the 

 nucleoli of the polars are fusing; X1560. 



Fig. 15. — Pollen tube in region of synergid, and egg in division; endo- 

 sperm cell has made one division; X920. 



Fig. 16. — A 2-celled proembryo, while the endosperm cell is in first 

 division; X920. 



Fig. 17. — A 2-celled proembryo; 5 endosperm nuclei were counted; 

 X920. 



* 



Fig. 18. — A 3-celled proembryo; X920. 



Fig. 19. — Proembryo has divided by vertical walls; X750. 



Fig. 20. — Dermatogen is cut off; X750. 



Fig. 21.— The massive proembryo with no line of separation between 

 embryo and suspensor ; X 540. 



Fig. 22. — Median longitudinal section of a sterile ovule; embryo sac 

 replaced by vegetative cells; X 1200. 



Trifolium hybridum 



Fig. 23. — Early germination of lower megaspore; X 1500. 



Fig. 24. — An 8-nucleate embryo sac; cytoplasm of the sac forms a 

 marginal layer around the large vacuole; polars in contact on inner side of 

 sac; X910. 



Fig. 25.— Proembryo with cotyledons appearing; the stalk is composed 

 of large cells, and there is an apparent line of separation between suspensor 

 and embryo at this stage; X540. 



Fig. 26. — Remains of suspensor on the hypocotyl of the embryo; X53°- 

 Fig. 27.— Ovule showing the long, curved embryo sac, and proembryo 

 in early stage; X360. 



Trifolium re pens 



Fig. 28. — Reduction division of mother cell; outer integument well 



00 



— One 



500 



200 



Fig. 30. — third megaspore functioning; X 



Medicago sativa 

 Fig. 31. — Young nucellus with 3 sporogenous cells, each capped by one 



500 



synapsis 



500 



Fto- 33-— Mother cell in reduction division; parietal cell has divided 

 versely; X1500. 



Fig. 34. — Two rows of megaspores; X1500. 



F * G - 35- — Two embryo sacs; one is binucleate; X1500. 



