104 Campbell . — The Embryo- Sac of Peperomia. 
It seemed desirable, therefore, to examine the subject again, 
and a number of new preparations were made, to supply 
certain stages which were lacking in the series of slides 
made for the preliminary examination. In preparing these, 
Flemming’s triple stain was employed, which gave much 
better results than the simpler aniline-water safranine, which 
had been used before. From a study of these new prepara- 
tions it was soon evident that Johnson’s conclusions were 
substantially correct, although there were one or two minor 
points with which the writer’s results do not agree. 
In the former paper, the writer asserted that no endosperm 
was formed, and that in the ripe seed the embryo filled the 
whole embryo-sac. The error arose from a failure to find the 
stages between the very young embryo, and the stage where 
the embryo apparently filled the whole sac. The embryo is 
small, and its cells closely resemble those of the large-celled 
endosperm. As Johnson has shown, certain of the nuclei take 
no part in the endosperm-formation, and these being seen 
crowded against the walls of the embryo-sac by the globular 
mass of large-celled endosperm, the latter was mistaken for 
an embryo, which had filled up the embryo-sac, without any 
endosperm being formed. 
The Flower. 
The flower in Peperomia is exceedingly simple, the gynoe- 
cium consisting of a single carpel with a solitary erect ovule, 
having but a single integument. Two stamens are present, 
and the flowers, which are set on thick spadix-like spikes, are 
each subtended by a peltate bract. 
The development of the flower is easily followed in longi- 
tudinal sections of the young spike, and it was found to agree 
with the account given by Schmitz 1 . 
The ovule develops a single large archesporial cell 2 , from 
which a single tapetal cell is cut off, which undergoes repeated 
1 Die Bliithenentwickelung der Piperaceen ; Hanstein, Bot. AbhandL, ii, i, 
1872. 
2 Campbell, loc. cit., Figs. 1, 2. 
