324 The Ohio Naturalist. [Vol. V, No. 6, 



latter was not seen divided and its nucleus was quite vescicular 

 even m rather young embryos (Figs. 23-24). The abundant 

 endosperm completely surrounds the young embryo which at 

 first develops very slowly. The outer integument becomes very 

 hard, the inner one and the nucellus remaining very spongy and 

 giving way to the growing endosperm. Ovules which contained 

 mature embryos were found in the capsules of the previous year. 

 Hand sections showed a flat straight embryo with two cotyledons 

 (Figs. 20-27). There was no endosperm layer between the 

 cotyledons. The hardening of the outer integument agrees with 

 the observations of Guerin on Staphylea in his study of the seed 

 integuments of some Sapindales. He also notes abundant 

 "albumen" in both Staphylea and Melianthus. 



I wish to acknowledge my great indebtecbiess to Professor 

 J. H. Schaffner for his invaluable assistance, and to express my 

 hearty ap])reciation of his kindness. 



Bibliography. 



Coulter & Chamberlain. Mor])hology of Angios])erms.l9()3. 



GoEBEL. Outline Classification and Special Morphologv. 



Guerin, F. Developpement de la graine et en particulier, du 

 tegument seminal de quelques Sapindacees. Journal de Bot- 

 anique, 1901: No. 10-11. 



Mottier, D. B. Development of the embryo sac in Acer rub- 

 rum. Bot. Gaz. 18:375-377. 



Strasburger, Ed. Ueber Zellbildung und Zelltheilung. Jena 

 Zeitschr. f. Naturw. Bd. XIII, Suppl. Heft 2, p. 50. 188(f. 



Strasburger, Ed. Neue Untersuchungen ueber den Be- 

 fruchtungsvorgang bei den Phanerogamen. Jena. bSS4. 



Explanation of Plates. 



For the figures 1-15 a Leitz microscope with No. ocular and 

 No. 7 objective for all but Figure 14 which was drawn with a 

 lower power. A Bausch and Lomb instrument was used for all 

 the other drawings. For Figure IG the 1-2 ocular and 1-12 oil 

 immersion were used. For Figure 17 the 1-in. ocular and 1-12 

 objective; for Figures 18-22 the l-in. ocular and 1-0 objective; 

 for Figures 23-24 a 2-in. ocular and l-() objective and for Figures 

 25-27 the 2-in. ocular and the u|)|)er lens of the 2-3 objective. 



plate XIX. 



Fiti^. 1. Archesporial cell. 

 Fig. 2. Three celled archesporium. 



Fisr. :>. Primary jiarielal cell and nu\c^as])()rocytc. Integuments 

 beginning t(j develop. 



Fig. 4. Three tapetal cells and megasporocytc. 

 F"ig. ."). Two tapetal cells; megas])orocyte enlarging. 

 Figs. ()-7. Four and live ta])etal rvUs. 

 Fig. 8. I'onr tajjctal cells and lour megasporcs. 



