BETA VULGARIS z8i 



peripheral position in the embryo sac. Wall formation follows, 

 and, finally, the entire sac is filled with storage cells which are 

 later resorbed by the growing embryo except for a single layer 

 surrounding the hypocotyledonary portion of the embryonic axis. 

 This persistent layer consists of small, very regular cells with dense 

 contents. At the time that the curved embryo sac has reached 

 its final form and size, the peripheral layer of nucellar tissue is four 

 to six cells in thickness; but as the embryo enlarges, the inner pe- 

 ripheral layers are gradually resorbed. The remaining cells of the 

 perisperm ultimately become packed with large starch grains except 

 in the chalazal region. 



LITERATURE CITED 



I. Artschwager, E., "Anatomy of the vegetative organs of the sugar beet." 



Jour. Agr. Res. )^: 143-176, 192.6. 

 1. , "Development of flowers and seed in the sugar beet." Jour. Agr. Res. 



54- 1-2-5 > 192-7- 



., and Starrett, Ruth C, "The time factor in fertilization and embryo 



5 



development in the sugar beet." Jour. Agr. Res. 47: 82.3-843, 1933. 

 Bailey, L. H., The Standard Cyclopedia of Horticulture, 1-468, The Macmillaii 



Co., 1914. 

 DE Bary, a., a Comparative Anatomy of the Vegetative Organs of the Phanerogams 

 and Ferns, Clarendon Press, Oxford, 1884. 



6. Bennett, C. W., and Esau, Katherine, "Further studies on the relation 



of the curly top virus to plant tissues." Jour. Agr. Res. sh' 595-610, 1936. 



7. Esau, Katherine, "Ontogeny of phloem in the sugar beet (Beta vulgaris L.\" 



Am. Jour. Bot. 21: 631-644, 1934. 



8. Fron, M. G., "Recherches anatomiques sur la racine et la tige des Cheno- 



podiacees." Ann. Sci. Nat., Bot. Ser. VIII, p.- 157-140, 1899. 



9. van Heel, J. P. D., "Onderzoekringen over de ontwikkeling van de anthere, 



van den zaadknop en van het zaad bij Beta vulgaris L. Naarden." (Thesis, 

 Delft}, 1915. 



10. Janczewski, E., "Recherches sur I'accroissement terminal des racines dans 



les Phanerogames." Ann. Sci. Nat., Bot. Ser. V, 20: 161-101, 1874. 



11. Lyle, Elizabeth A., "The structure and development of the seedling of Beta 



vulgaris L." Unpub. M.S. Thesis, Univ. of Chicago, 1937. 

 II. Matthysen, J. O., "Cytologische und anatomische untersuchungen an Beta 

 vulgaris, nebst einigen Bemerkungen iiber die enzyme dieser pflanze." 

 Ztschr. Ver. Deut. Zuckerindus. (n. F. 49) 62Q2): 137-15 1, 1911. 



13. OvERPECK, J. C, "Methods of seed production from sugar beets overwintered 



in the field." U. S. Dept. Agr. Cir. 7/5, 1931. 



14. Payer, J. B., Traite d' organogenic comparee de la fleur. Text and atlas, 2 v. 



Paris, 1857. ^ 



15. Plaut, M., "Epiblem, Hypodermis und Endodermis der Zuckerriibe." 



Kaiser-Wilhelm Inst, fiir Landw. Bromberg. j.- 63-68, 1910. 



