340 Campbell. — Studies on the Araceae , III. 
In Fig. 45 is shown a sac in which there were two large nuclei 
surrounded by small starch granules such as are usually found after the 
fusion of the polar nuclei. These nuclei were separated by a delicate cell- 
membrane, but whether this was a real cellulose wall was not determined. 
There was in this specimen a second young embryo-sac with a single 
nucleus. 
Of somewhat similar character is the case shown in Fig. 43. In this 
case the embryo-sac showed a transverse division into three parts. It is 
possible that here each division is really a potential embryo-sac, but if this 
is true, the definitive embryo-sac is formed by the fusion of three primary 
ones. Of the three divisions, the upper and lower ones each contained two 
nuclei, while the middle one had but a single one. There was in this case 
also a single sac (sp 2 .), much smaller, but containing two nuclei. From its 
small size and position it is pretty certain that it would eventually be 
destroyed by the growth of the principal sac. 
The embryo-sac shown in Figs. 54, 55 * s °f somewhat the same 
character as that figured in 43. In the upper compartment a hemispherical 
mass of cytoplasm, probably the egg-cell, could be seen : there were also in 
this compartment two other nuclei (cd.) t which perhaps may be interpreted 
as belonging to synergidae. In the large central compartment there were 
four free nuclei, and in the lower compartment was a group of apparently 
five cells looking like antipodal cells. If the whole structure represents 
a single embryo-sac, it contains twelve nuclei, instead of the eight 
characteristic of the typical Angiosperms. 
A decidedly different type is shown at Figs. 57-59. The embryo-sac 
in this instance was not divided by walls, but above it was a small sac with 
five nuclei. It is possible that these five nuclei were not all contained in 
a single sac, and there may have been two of the secondary sacs very close 
together. In the upper part of the principal sac (Fig. 57) was a group of 
apparently three nuclei in process of fusion, below these being two other 
free nuclei. Near the base of the sac, but at one side, was an irregular 
group of either four or five cells (Fig. 58), each with a single nucleus. At 
the extreme base were three other cells (Fig. 59) closely resembling normal 
antipodal cells. In this instance it was impossible to say from which of 
the two lower groups of cells the egg-cell would be derived, but it is clear 
that it would not be formed in the upper part of the sac, as is usually 
the case. 
The fusion of three nuclei presumably antecedent to the endosperm 
formation, together with the presence of three extra free endosperm nuclei, 
have their nearest analogy, perhaps, in Peperomia , and are to a certain degree 
between the condition found in the latter genus and that which obtains 
in the ordinary Angiosperms. 
Another different type is shown in Fig. 53. In this specimen there 
