306 INTRODUCTION TO EMBRYOLOGY OF ANGIOSPERMS 



Four saprophytic members of the Gentianaceae, studied by Oehler 

 (1927) are also of much interest in this connection. In Voyriella 

 parviflora the first division of the zygote takes place when the endo- 

 sperm is composed of 10 to 12 cells. A filamentous proembryo of 

 six or seven cells is formed. Of these, the three or four terminal 

 cells divide further to give rise to a mass of 16 to 24 cells. Cotylan- 

 thera tenuis (Fig. 1750) and Voyria coerulca are similar but somewhat 

 more reduced. They have a suspensor of three or four cells and an 

 embryonal portion consisting of about a dozen cells. The most 

 reduced of the four is Leiphaimos spectabilis in which only the 

 terminal cell of the four-celled embryo divides again, so that at the 

 shedding stage of the seed the embryo consists of no more than five 

 cells arranged in four tiers (Fig. 175P). 



Reduced embryos without the usual organization into a radicle, 

 plumule, and cotyledons have also been described in Ranunculus 

 ficaria (Soueges, 1913) (Fig. 176), Corydalis cava (Hegelmaier, 

 1878), and a few other plants, although these are not characterized 

 by a parasitic or saprophytic habit. 



References 



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



embryo development in the sugar beet. Jour. Agr. Res. 47: 823-843. 

 Avery, G. S., Jr. 1930. Comparative anatomy and morphology of embryos and 



seedlings of maize, oats and wheat. Bot. Gaz. 89: 1-39. 

 Bhaduri, P. N. 1936. Studies in the embryology of the Solanaceae. I. Bot. Gaz. 



98: 283-295. 

 Bianchi, R. 1946. Untersuchungen liber die Fortpfianzungsverhaltnisse von 



Gagea fistulosa (Ram.) unci Lloydia serotina (Rchb.). Diss. Zurich. 

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Daucus carota. Bot. Gaz. 92: 23-44. 

 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. 

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di Bot. 18: 145-166. 

 Carano, E. 1915. Ricerche sull'embriogenesi delle Asteraceae. Ann. di Bot. 



13: 251-301. 

 Carlson, E. M., and Stuart, B. C. 1936. Development of spores and gameto- 



phytes in certain New World species of Salvia. New Phytol. 35: 65-81. 

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