144 INTRODUCTION TO EMBRYOLOGY OF ANGIOSPERMS 



In several members of the Centrospermales (Oksijuk, 1927; Art- 

 schwager and Starrett, 1933; Joshi, 1936; Cooper, 1949) the em- 

 bryo sac pushes forward at the chalazal end and digests its way 

 through the nucellus, while the antipodal cells remain in situ and 

 are left behind in a lateral position (Fig. 94E). This "caecum," 

 which is also known in Allium (Modilewski, 1928) (Fig. 94A-C), 

 Elegia (Borwein, et al., 1949), Macrosolen (Maheshwari and Singh, 

 1950), and certain other plants (see Finn, 1936), seems to be a very 

 effective haustorial organ. 



In Veltheimia (Stiffler, 1925; Buchner, 1948), Paradisia (Stenar, 

 1928), and Eucomis (Buchner, 1948) the haustorium arises laterally 

 rather than from the pole of the embryo sac. As a rule, however, 

 such a condition is met with only in postfertilization stages and will 

 therefore be considered in the chapter on the endosperm. 



References 



Afzelius, K. 1916. Zur Embryosackentwicklung der Orchideen. Svensk Bot. 



Tidskr. 10: 183-227. 

 . 1924. Embryologische und zytologische Studien in Senecio und ver- 



wandten Gattungen. Acta Horti Bergiani 8(7): 123-219. 

 Arnoldi, W. 1912. Zur Embryologie einiger Euphorbiaeeen. Trav. Mus. Bot. 



Acad. St. Petersburg 9: 136-154. 

 Artschwager, E., and Starrett, R. C. 1933. The time factor in fertilization and 



embryo development in the sugar beet. Jour. Agr. Res. 47: 823-847. 

 Bambacioni, V. 1928a. Ricerche sulla ecologia e sulla embriologia di Fritillaria 



persica L. Ann. di Bot. 18: 7-37. 

 . 19286. Contribute alia embriologia di Lilium candidum L. R. C. Accad. 



Naz. Lincei 8: 612-618. 

 Bambacioni-Mezzetti,V. 1931. Nouve ricerche suH'embriologia delle Gigliaceae. 



Ann. di Bot. 19:365-382. 

 Bergman, B. 1935. Zytologische Studien tiber die Fortpflanzung bei den Gat- 

 tungen Leontodon und Picris. Svensk Bot. Tidskr. 29: 155-301. 

 Borwein, B., Coetsee, M. L., and Krupko, S. 1949. Development of the embryo 



sac of Restio dodii and Elegia racemosa. Jour. South AM. Bot. 15: 1-11. 

 Boyes, J. W. 1939. Development of the embryo sac of Plumbagella micrantha. 



Amer. Jour. Bot. 26: 539-547. 

 Brough, P. 1924. Studies in the Epacridaceae. I. The life history of Styphelia 



longifolia (R.Br.). Proc. Linn. Soc. N. S. Wales 49: 162-178. 

 Brown, W. H., and Sharp, L. W. 1911. The embryo sac of Epipactis. Bot. 



Gaz. 52: 439-452. 

 Buchner, L. 1949. Vergleichende embryologische Studien an Scilloideae. Osterr. 



bot. Zeitschr. 95: 428-450. 



