THE FEMALE GAMETOPHYTE 



141 



paratus and rarely even in the antipodal cells. The following are 

 some examples of the occurrence of starch grains in the egg: Astilbe 

 grandis (Dahlgren, 1930), Aspidistra elatior (Golaszewska, 1934), 

 Acacia baileyana (Newman, 1934), Medicago saliva (Cooper, 19356; 

 Cooper, Brink, and Albrecht, 1937), Korthalsella opuntia (Rutis- 

 hauser, 19376), Zea mays, 

 Euchlaena mexicana (Cooper, 

 1938), Portulaca oleracea 

 (Cooper, 1940), and Phryma 

 leptostachya (Cooper, 1941). 

 In Korthalsella (Rutishauser, 

 19376) starch is also found in 

 antipodal cells. 



In Sonneratia (Venkates- 

 warlu, 1937; Mauritzon, 1939) 

 certain oily bodies of an un- 

 known nature persist from the 

 megaspore mother cell stage to 

 the formation of the mature 

 embryo sac, and in Aspidistra 

 (Fig. 92) (Golaszewska, 1934) 

 large raphides have been seen 

 in the mature stages. The 

 significance of these structures 

 in the economy of the embryo 

 sac has not been elucidated up 

 to this time. 



Embryo Sac Haustoria. In 

 the majority of angiosperms 

 the entire surface of the em- 

 bryo sac serves an absorptive 

 function, demolishing the ad- 

 jacent cells of the nucellus and 

 even the inner layers of the 

 integument. In some plants, 



however, more active growth 



., , „ ,, Fig. 92. Embryo sac of Aspidistra elatior, 



is seen at the ends of the sac. , • + , • , i WA 



showing starch grams and a large raphide. 



In Phaseolus (Fig. 93 A) (Wein- (After Golaszewska, 1984). 



