Embryo in Lilaea subulata , H. B. K. 17 
protoplasm is more abundant, but contains numerous vacuoles. 
The nucleus is, as we have said, much larger than those of the 
synergidae, and contains more chromatin. The nucleolus is 
large, and in stained sections shows a vacuolated appearance. 
The large endosperm-nucleus is lenticular in form and has 
very little chromatin, but the very large nucleolus stains 
strongly and is much like that of the egg-cell. In the 
specimen figured there were two small bodies {cen.) lying 
near the nucleus which may possibly have been centrospheres ; 
but they were not very conspicuous, and it is doubtful, at 
least, whether they can really be considered as such. They 
were not seen associated with the other nuclei in the embryo- 
sac, so that it must be considered questionable whether they 
were really centrospheres or only granules belonging to the 
cytoplasm. 
While nearly all the embryo-sacs examined showed the 
normal structure just described, evidences of a deviation from 
this were seen in a few cases. The most marked was the one 
shown in Fig. 30. Unfortunately the structure of the lower 
part of the sac could not be clearly made out, as the series of 
sections was not complete. In the upper part of the sac, 
which was blunter than in the normal form, there was an 
irregular cellular mass, showing imperfect cell-walls. Eight 
nuclei could be certainly made out, but no trace of the definite 
egg-apparatus or other special structures usually found in 
the embryo-sac. Whether in the missing sections there were 
more nuclei than those seen, cannot be stated, but it is not 
impossible. Whether there were more than the normal 
number of nuclei, or not, the filling of the upper part of the 
sac with a cellular structure is a marked departure from 
the normal structure. Similar abnormal cases have been 
observed by the writer in Naias Jiexilis , Zannichellia palustris , 
and Sparganium eurycarpum ; but otherwise, exceptions of 
this kind seem to have escaped observation. 
C 
