Of Aphyllon Unifiorum, Gray. 119 
a clearly-marked nucellus, while the primine has grown 
nearly around the nucellus. Up to this stage there has 
been clearly no formation of tapetal cells, and (although my 
material was too badly shrunken to be very satisfactory) I have 
reason to doubt their formation at any time. I have observed 
many completely anatropous ovules, which contained within 
the three cell layers one much elongated, darkly-staining 
mass of protoplasm. Many of these showed two nuclei, but 
a clear unmistakable transverse wall could not be observed. 
Koch, in his ‘‘Entwicklungsgeschichte der Orobanchen,” 
figures for O. speciosa the division of the macrospore-mother- 
cell into four, of which the upper one is the macrospore ; and 
this division occurs when the ovule is turned half-way. If 
the macrospore-mother-cell does divide in Aphyllon, the divi- 
sions must occur at a much later period than they do in the 
related species described by Koch. 
Plate XV, Fig. 3, shows a much older ovule. The integu- 
ments fully surround the nucellus, and the outer one is closely 
packed with starch, while the nucellus is pressed against by 
the structures within. Owing to the lack of closely preced- 
ing stages this ovule cannot be interpreted with complete cer- 
tainty as yet. The probable interpretation, based upon the 
development of related plants, is as follows: The multicellular 
cell-body represents the mass of precociously developed 
endosperm, which has grown up around the egg-cell intoa 
neck-like structure. The central cell is the egg, still unseg- 
mented, and the long, plug-like body filling the apparent neck, 
is the suspensor, consisting of two cells. At the opposite 
end of the ovule, one cell represents the remnant of the 
antipodal cells, which have become shrunken. Such forma- 
tion of precocious endosperm is common throughout the 
Orobanchacee, and in Aphyllon it seems to take place to a 
greater degree than in QO. speciosa, as described by Koch, 
where the neck-like upgrowth of the endosperm around the 
suspensor is much less perfectly developed than in Aphylon. 
