1909] PACE—GAMETOPHYTES OF CALOPOGON 131 
FERTILIZATION 
As has been said, the embryo sac when ready for fertilization con- 
tains eight nuclei, arranged in the usual fashion—the egg apparatus 
of two synergids and an egg in the micropylar end, three antipodals 
at the opposite end, and the two polars about the center of the sac 
(jig. 53). When the pollen tube is entering the sac, the egg and the 
polar nuclei may be in late spirem stage (fig. 54). In fig. 55 the two 
polars have already formed chromosomes. Fig. 56 shows the fusion 
of a male nucleus with the egg, and the triple fusion in the center of 
the sac is undoubtedly that of the two polars and the second male nu- 
cleus. Not very much material was examined at this stage. But in 
all that was seen there was every indication that this is the usual 
condition. 
DISCUSSION 
Sporogenous cells—BowER (3) states that a multicellular arche- 
sporium is found in several of the archichlamydeous dicotyledons, 
especially in Amentiferae, Rananculaceae, Rosaceae; but that it is 
apparently rare in more advanced dicotyledons and in the monocoty- 
ledons. GuIGNarD (g) reports Ornithogalum pyrenaicum with an 
archesporium of two cells, only one of which gets beyond the arche- 
Sporial stage. BARNARD (1) reports two embryo sacs in Lilium can- 
didum. CouLTER and CHAMBERLAIN (7, p. 61) say that they have seen 
one preparation of Lilium philadelphicum with three archesporial 
cells and another with five; but no figures are given. FERGUSON 
(8) in a note figures two mother cells in Lilium longiflorum with 
intervening nucellar tissue. But, as has already been shown, there are 
many such cases in Calopogon, thirty-seven cases of two mother 
cells or stages evidently derived from them being seen, in thirteen 
ovaries out of about sixty cut, and this probably represents less than 
half the number actually present. So while this condition is very far 
from being the usual one in my material, it could hardly be called 
rare, and therefore abnormal. It seems best to regard it as a primitive 
character that has been retained, or at least not entirely eliminated. 
SARGANT (1) and others hold that monocotyledons are derived from 
dicotyledons. This occasional appearance of a multicellular arche- 
sporium may indicate that the dicotyledons from which these came 
