626 
Notes. 
A PECULIAR EMBRYO-SAC TN PEPEROMIA PELLU- 
CIDA. — During a preliminary study of the development of the ovule 
and embryo-sac of Peperomia pellucida, I was struck by certain 
remarkable peculiarities, which seemed to be perfectly constant, and 
while all the details have not yet been worked out, it is evident 
that in this plant we have a form which differs remarkably from 
the usual Angiospermous type. 
The origin of the embryo-sac shows nothing unusual, but after 
the first division of the primary nucleus a difference is manifested. 
The young embryo-sac is small, and broadly oval in outline, with 
a relatively very large nucleus. After the first division of the latter, 
the two daughter-nuclei remain close together, and after the next 
division, the four resulting nuclei are arranged at equal distances 
from each other, very much as in the ordinary tetrad- division of 
spore-mother-cells. This stage is followed by one with eight nuclei, 
arranged equally about the periphery of the sac, which is completely 
filled with granular cytoplasm without the usual central vacuole. 
Absolutely no trace of the polarity, so characteristic of the usual 
embryo-sac, can be detected, nor is there any sign of a definite 
egg-apparatus, of antipodals, or of polar nuclei. About this time the 
central vacuole is formed, and soon afterwards another nuclear 
division takes place, resulting in sixteen free nuclei, distributed equally 
about the periphery of the sac, in the rather thick cytoplasmic layer. 
Whether in any case more than sixteen nuclei are present before 
fertilization remains to be seen — nor is it yet quite clear just what 
is the origin of the ovum. 
That the structures here described are formed before fertilization is 
not to be doubted. The closely set flowers make it very easy to 
follow the successive stages in longitudinal sections of the flower- 
spike, and unbroken series of stages have been repeatedly followed. 
The further development also presents some apparent anomalies, 
but these have not yet been studied with sufficient care to warrant 
any positive statements. 
The material used was collected at the Royal Gardens, Kew, and 
my sincere thanks are due to the Director for this, as well as much 
other material. 
D. H. CAMPBELL. 
Dresden, November , 1899. 
