640 Wisconsin Academy of Sciences, Arts, and Letters. 
thickening as should occur at this period on the theory of 
Farmer and Moore. 
Mottier (67) though a supporter of the Farmer and Moore 
hypothesis is of the opinion that the segmentation of the spirem 
may take place at the periphery as well as in the central region 
of the nucleus. The central segmentation of the spirem appears 
however to be an essential part of the Farmer and Mbore hy¬ 
pothesis. Very serious mechanical obstacles interfere with the 
looping and lateral approximation when segmentation occurs 
away from the central region. The looping of the spirem in 
the peripheral regions of the nucleus which is open and rela¬ 
tively free from spirem strands at this period seems to be the 
only method and the only position in which looping could be 
brought about. In the central region the presence of the ag¬ 
gregation of spirem strands prohibits looping until after the 
segmentation of the spirem and the breaking up of the central 
aggregation. It is difficult to conceive of the looping of spirem 
segments after segmentation and such a process has thus far not 
been described. 
There can be no doubt that in Smilacina there exists a defi¬ 
nite well marked second contraction period as a stage in the first 
reduction division. The survey of the literature indicates fur¬ 
ther that without doubt the phenomenon is more widespread 
than the attention which it has received would indicate. 
The view of Davis (18) that the second contraction stage is 
simply a continuation of synapsis does not correspond well with 
the observed facts in Smilacina. The stage of the uniformly 
expanded spirem found here has been described for the hetero¬ 
typic division in practically all the higher plants studied and 
lias nothing in common with synapsis according to the commonly 
accepted usage of the term. The shortening and thickening of 
the spirem may be a more or less uniform, continuous process 
from the time of its formation to diakinesis but to designate 
this whole period “synapsis” because contraction is going on is 
to give an entirely new meaning to the term. There are two 
distinct stages in which the spirem becomes wholly (synapsis) 
or partly (second synapsis) aggregated in a dense knot. It is 
