1918] PFEIFFER—THISMIA 355 
antipodal cells at the opposite end of the sac, while the 2 polar 
nuclei usually meet near the center, sometimes nearer the chalazal 
or micropylar end (as Burmannia Championii, 5). 
When the egg is mature, in some cases there is evidence of the 
entrance of a pollen tube with the discharge of two male cells, one 
of which fuses with the egg, the other with the polar nuclei, as 
B. candida. That the latter fusion is not a complete one is held by 
ERNstT and BERNARD, who see in a 3-parted nucleus with 3 nucleoli 
evidence against entire merging, at least in the first divisions of this 
endosperm nucleus. The fusion of the egg nucleus, however, is 
slower here than that of the 3 nuclei in the center of the sac. When 
there are 2~4 cells in the endosperm, the sex nuclei still remain dis- 
tinct in B. candida (5). Later the fertilized egg gives rise to an 
embryo of 2 or more cells, varying with the form studied. 
In cases where no fertilization has been observed there was 
development of seeds as indicated, except that no fusion save that 
of the polar nuclei occurred. Thismia javanica (3) and Burmannia 
coelestis (2), examples in which this condition holds, show no reduc- 
tion division in the formation of the ‘‘megaspore.”” This condition 
is the one to be expected from such work as has been done in par- 
thenogenetic angiosperms. The development of the seed is first 
evidenced in B. coelestis by the division of the endosperm nucleus, 
which usually results from the fusion of 2 polar nuclei; occasionally 
there are more than the two concerned, as 3-5, probably through 
the functioning of synergids or antipodal cells. Thereafter the 
development seems much as in sacs where fertilization has taken 
place. Ernst and BERNARD in their series of studies of Burman- 
niaceae report for B. coelestis, B. candida, B. Championii, Thismia 
clandestina, T. Versteegii, and T. javanica, practically the same sort 
of development in the endosperm region, regardless of the intro- 
duction of a male cell. The first division of the fusion nucleus gives 
rise to 2 nuclei, the lower of which is cut off by a wall. The cell 
thus formed is designated as the “basal apparat’’ or haustorium 
cell. The other nucleus, however, continues to go through succes- 
sive divisions in which no cell plate is formed, with the result that 
there are a number of free nuclei in the endosperm region. Walls 
then develop in this region at approximately the same time or a 
