OF CASTALIA ODORATA AND NYMPHAEA ADVENA 215 
scribes an enlargement of the sac with the three disorganizing 
antipodals in a small caecum-like structure. Riddle (11) in her 
Studies on Alyssum macrocarpum describes a decided enlargement 
of the sac, and an increase in the endosperm with a very pro- 
nounced accumulation of endosperm cells in the antipodal region, 
usually obscuring the antipodals which are very small and appar- 
ently functionless. 
In Schaffner’s studies of Sagittaria variabilis (12) we have a 
condition very nearly that found inthe Nymphaeaceae. The endo- 
Sperm nucleus divides and a wall is formed across the sac; the 
lower part of the sac does not enlarge greatly as in the Nymphaea- 
ceae and the antipodals persist but the nuclei resemble very closely 
those I have described for the Nymphaeaceae. 
We find further evidence on this point in the papers on Pota- 
mogeton by Wiegand (15) and by Holferty (8). Wiegand describes 
for P. foliosus (15) a sac of seven nuclei, three forming the egg ap- 
paratus and three the antipodals and one very large nucleus which 
he calls the fourth antipodal and states that a little later it divides 
into two and that a wall forms across the sac at this point, separat- 
ing the two nuclei thus formed. He furthermore states that the 
Upper of these two new nuclei divides forming the endosperm, the 
lower remaining undivided. Holferty describes P. natans (8) as 
forming the normal eight-celled sac and the polar nuclei as fusing 
in the normal manner. 
From these two papers it seems possible that Wiegand failed 
to observe the conjugation of the polar nuclei and that the division 
of the fourth large antipodal was really a division of the endo- 
Sperm nucleus as in Sagittaria and the Nymphaeaceae. 
It seems unreasonable to suppose that the antipodals are 
without physiological significance in those plants where they are 
Prominent. Inthe Ranunculaceae, in Sparganium, and in Vaillantia 
the antipodals appear to furnish nourishment for the embryo. The 
Peculiar haustorial development of the antipodal of Vaillantia, 
the enlargement of the lower antipodal in Aster, the accumulation 
“al endosperm in the antipodal region of Adyssum, and the large 
lower nucleus formed by a division of the endosperm nucleus in 
Sagittaria and the Nymphaeaceae show a resemblance which I be- 
e indicates similar physiological functions. The mere enlarge- 
