1899 | LIFE-HISTORY OF LEMNA MINOR 59 
nucleus (figs. 46, 48, 50); or they may fail to meet (fig. 55), 
in which case the upper polar nucleus seems to have been able 
to form endosperm cells without the assistance of the lower 
one. I was not able to determine whether the two cells below the 
Fic. 49. Micropylar end of sac; recently formed oospore ; part of pollen tube in 
sac and nucellus. X 1375 
Fic. 50. Sac with unusually large oospore. X 1375. 
Fic, 55. Sac with oospore, endosperm, and antipodals ; lower polar nucleus with 
antipodals. X 1375. 
FI Same as fig. 55, except the peculiar cells with the antipodals which may 
have come from division of lower polar nucleus. X 1375. 
egg apparatus in fig. 53 are endosperm cells or polar nuclei. 
An interesting case is shown in fig. 56, in which the upper cell 
is probably an oospore, while below it are five cells, evidently 
endosperm cells. Inthe antipodal end of the sac are the remains 
of the antipodals, and immediately above them two very large 
cells which have the cytoplasm somewhat definitely organized. 
They do not stain as disintegrating cells, but react in a manner 
quite different from the five cells above them. I am not able 
to speak confidently in reference to these cells, but it is quite 
possible that they may have resulted from the division of the 
lower polar nucleus, while the five cells above may be the 
progeny of the upper polar nucleus. 
