1900 | *-ENDOSPERM AND-EMBRYO OF PEPEROMIA 5 
divides by mitosis, the first spindle being approximately trans- 
verse. The number of chromosomes here is seemingly very 
large, compared with that in other spindles found in the 
embryo-sac or in the nucellus, but they were so densely packed 
in all the cases seen that it was impossible to make accurate 
counts. , : 
It is certain, however, that the amount of chromatin in this 
and its daughter spindles is greater than that found anywhere 
else in the plant (espn, figs. 9, rz). A cell plate is formed in 
the typical way at the middle of each spindle, the fibers of the 
latter being stretched out laterally to a surprising extent (espn, 
jig. 10). The new cell-wall thus formed stretches from the 
oospore to the base of the embryo-sac and cuts the latter com- 
pletely in two, forming thus two endosperm cells. Each of 
these divides further, forming a cell-wall immediately at each 
division, till in the oldest seeds seen there are forty or more 
endosperm cells, each with a large nucleus, several nucleoli, and 
dense cytoplasm, filling up all of the embryo-sac not occupied 
by the embryo and synergid and flattening the degenerating 
peripheral nuclei against the wall of the embryo-sac (esf, figs. 
12, 13, 14, pn; figs. 9, 13). 
The fusion of the sexual nuclei is completed, at the latest, 
soon after that of the nuclei of the endosperm group, and before 
many endosperm cells are formed the oospore divides to form the 
embryo. In the few cases of the early divisions of the embryo 
seen the first wall seemed to be longitudinal, and the position of 
the walls in the slightly older embryos, often seen, seemed to 
confirm this (em, figs. 12, 13). 
The oldest fruits available, as was evident from their position 
on the spike were nearly ready to separate from the mother plant, 
z. €., were nearly ripe. In these the embryo consisted of more 
than twenty cells, but showed no sign of a definite suspensor and 
no indication of the organs of the young sporophyte. In fact, 
the whole structure has much the same shape and but slightly 
larger size than the one-celled oospore (asp, fig. 9, em, figs. 
12,17). 
