98 MORPHOLOGY OP ANGIOSPERMS 



In other instances the activity of the antipodal cells is 

 shown by their great increase in size and usually multinucleate 

 condition, and also by their more or less extensive division. 

 Among the Monocotyledons, the Sparganiaceae, Gramineae, 

 and Araceae are conspicuous for their strongly developed antip- 

 odal cells. In Sparganium simplex Campbell 63 describes the 





Fig. 45. — Sparganium simplex. Lower end of embryo-sac showing a large mass of 



antipodal cells. — After Campbell. 63 



antipodal cells as at first very small, but immediately after 

 fertilization they enlarge to several times their original size, 

 their nuclei dividing. Finally, a conspicuous hemispherical 

 mass of 100 to 150 uninucleate cells is formed, at this stage the 

 endosperm having hardly at all developed (Fig. 15). The 

 strong development of antipodal cells among the Gramineae 

 has long been known, Fischer 6 having reported in 1880 that 

 each antipodal cell of Ehrarta panicca divides once, and of 

 Alopecurus pratensis three or more times. More recently 

 Cannon 86 found in Arena fatua that the antipodal cells be- 

 come thirty-six or more in number before fertilization, and 

 begin to disorganize with the beginning of endosperm devel- 

 opment. Westermaier 23 has described a growth of antipodal 

 tissue in Zea and other grasses before fertilization, and 

 Guignard n0 has found as many as twelve multinucleate cells 

 in the much narrowed antipodal end of the embryo-sac of 

 Zea. It is of interest to note in this connection that in 1882 

 the same investigator 12 found in Cornucopiae undivided but 

 prominent and often binucleate antipodal cells. Among the 

 Araceae Campbell 78 states that there is a general tendency for 

 the antipodals to develop strongly, often dividing and forming 

 a tissue, and in Lysichiton himtschatccnse the same observer 63 

 finds that at the time of fertilization the antipodal nuclei have 



