of Some Embryo-sacs. 85 
seen that the chromosomes are composed of a number of 
quite evident granules. This granular structure of the 
chromatin cannot be seen in the later stages of mitosis. 
The nucleoli vary in number from one to as many as three 
in Scilla or seven in Lilium. The nucleoli are quite frequently 
surrounded by a clear zone filled with nuclear sap. The 
nucleolus has a dense homogeneous appearance and in Lilium 
may exhibit a number of small yellowish oil-like bodies 
embedded in its substance. In preparations stained with a 
single stain like Delafield’s Hematoxylin the nucleolus stains 
much more deeply than the chromatin. If sections stained in 
Hzmatoxylin be now stained in Eosin the nucleoli become red 
while the chromatin still remains blue. This would indicate 
that the nucleoli are of a different chemical nature from the 
chromatin, since they readily part with one stain for another. 
The chromatin holds stains tenaciously. Hence if the 
nucleolus was simply a very condensed mass of the chroma- 
tin, we would expect that chromatin would the sooner part 
with its Hzmatoxylin for the Eosin. Such, however, is the 
reverse of what happens. 
In some studies of mitosis in the Basidiomycetes, Wager 
describes the nucleolus as becoming smaller in size and the 
chromosomes increasing in size in proportion as the nucleolus 
becomes smaller. The nucleolus takes on a fainter stain as it 
becomes smaller; while the chromosomes, which originally 
stained differently from the nucleolus, now take on the same 
staining properties as the nucleolus originally possessed. He 
accordingly comes to the conclusion that the nucleolus is 
probably similar in nature to the chromatin. I have failed to 
observe anything which would tend to confirm this view. 
The centrosome question, as far as the Spermatophyta go, 
seems almost as far from solution as ever. Since Guignard 
first described centrosomes in Lz/ium Martagon, quite a number 
of workers have applied themselves to this problem. One of the 
most recent papersis that by Mottier on Li/zum and Podophyllum. 
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