368 BOTANICAL GAZETTE [NOVEMBER 
of the nucleus. Some investigators, however, do not regard it in 
this light. For example, LAwson? makes the following statement. 
Dyrmg — 4 noneret, Sapit: is a awa accumulation of sap 
within t e pressure, 
acting from within, cots the nuclear cavity to expand. This expansion con- 
tinues until the nuclear cavity grows to twice or even three times the original 
size. As the growth proceeds the membrane is gradually withdrawn from the 
chromatin mass within. The result of this withdrawal of the nuclear membrane 
is the formation of a large clear area of nuclear sap containing the mass of 
chromatin which has been left at one side. No evidence whatever was found 
to show that any contraction of the chromatin had taken place. 
In my material of D. Kaki I could not recognize such a remark- 
able enlargement after the chromatin reticulum began to separate 
from the nuclear b . The great enlargement of the nucleus 
occurs in the resting stage, so that there is no conspicuous differ- 
ence in the size of the nucleus at the synapsis stage and at the end 
of the resting stage, as LAWSON indicates. 
The synapsis stage is a normal occurrence, and during it there 
is some rearrangement, but not fusion of chromatin bodies, which 
results in the spireme stage. At the beginning of the spireme 
stage the thread is distributed in the outer cavity of the nucleus, 
where thickening and shortening occur, resulting in the diakinesis 
stage (pl. figs. 6, 7, 8). There is no difference in the size of the 
pairing chromosomes, which are usually parallel, but sometimes 
X or V-shaped. At the same time there appear in the cytoplasm 
numerous fibers which penetrate the nuclear cavity and become 
attached to the chromosomes by one end, in connection with 
which the nuclear membrane begins to disappear. By the elonga- 
tion of the fibers the chromosomes, which have been distributed on 
the surface of the nucleus, are drawn into the center of the nuclear 
cavity, and there are arranged in an equatorial plate by the gather- 
ing of the free ends of the fibers at the poles (pl. figs. 9, 10, 11). 
The nucleolus disappears entirely during metaphase. 
The number of chromosomes is difficult to count by reason of 
their small size. Usually there are. 28 in pairs, but sometimes 
* Lawson, A. A., The phase of the nucleus known as synapsis. Trans. Roy. Soc. 
Edinburgh 47:591-604. pis. 2. 1911. 
