84 McKenney—Observations on the Development 
In the development of its ovule, Sc//a may be said to differ 
from most plants in having a second macrospore undergo 
partial germination. In those species which develop more 
than one embryo-sac, each embryo-sac is developed as a rule 
from a separate archesporium. In Sc/a the rudimentary 
second embryo-sac is developed from the same archesporium 
as the normal embryo-sac. Commonly it is the lowest cell of 
the chain of archesporial daughter cells which becomes the 
embryo-sac. In Sci//a, however, the lowest cell of the chain 
forms the second rudimentary embryo-sac, while the normal 
embryo-sac is developed from the cell above this. 
CyToLoecy. 
The larger part of my cytologic study was made on Lilium 
as its cells are much larger than those of Scilla. Scilla, how- 
ever, shows essentially the same cell structure as Lilium. The 
cytoplasm of the archesporial cells of Lz/zum and Scilla reveals 
a well-marked reticulum or net-like structure, that of Scz/a 
having the reticular threads more closely woven together. 
The reticular threads appear to be made up of very minute 
stainable granules embedded in a less stainable substance. At 
the point of crossing of the reticular threads there is usually 
seen a larger granule. In Lz/zum there can usually be seen a 
number of small bodies scattered irregularly through the 
cytoplasm which stain very much like the nucleoli. The 
cytolymph is comparatively small in amount in archesporia, 
but gradually increases during development, until it occupies 
the larger part of the embryo-sac. 
The nucleus is always surrounded by a definite membrane 
which does not show any pores such as described by Mann. 
In some cases the chromatin seems to have a loose reticular 
structure, in others it appears in scattered irregular masses, 
and in still other cases it has the appearance of a thick twisted 
thread. The chromatin of resting nuclei has a homogeneous 
appearance, but during the early stages of mitosis it can be 
