1906] COOK—CUBAN NYMPHAEACEAE 385 
except that there are usually not more than four cells in the pro- 
embryo, With the formation of the spherical embryo the suspensor 
increases in diameter and the cells usually divide longitudinally 
(figs. 24, 25, 26). After the spherical stage the embryo gradually 
assumes a pear-shape, and a little later develops the collar-like 
ridge which extends about two-thirds around the embryo at its 
greatest circumference. This condition was readily demonstrated 
by two series of longitudinal sections cut at right angles to each 
other and a series of cross sections (figs. 27-30). Fig. 27 is from a 
longitudinal section passing through the middle (#) and between the 
two points of the crescent-shaped cotyledonary ridge (y). Fig. 28 is 
from a longitudinal section at right angles to jig. 27 and passes 
through the cotyledonary ridge near the points of the crescent (2). 
Fig. 29 is from a series of cross sections of an embryo of corresponding 
age to figs. 27 and 28. Fig. 30 is from section d of fig. 29, i, & at 
about the point where the cotyledonary ridge arises. Fig. 31 is 
reconstructed from a series of sections of a slightly older embryo. 
At this time there was no external indication of the two cotyledonary 
lobes, but the rapid division of cells just within the points of the 
crescent-shaped cotyledonary ridge (fig. 30¢, 1) indicates their early 
formation. 
It was impossible to follow the development of the embryo beyond 
this point, because of the withdrawal of the seed pods from the sur- 
face of the water to the bottom, where they were quickly buried in 
the mud. This withdrawal commenced soon after pollination and 
was accomplished by the spiral-like formation of the peduncle which 
gradually contracts, However, SCHAFFNER (26) was able to dissect 
the young embryos of Castalia odorata out of their sacs and makes 
the following statement concerning them: 
apparent. There is the same opening on one side, and on the back a connection 
of the two lobes, only to a less extent. Unless special care were taken in recon- 
