610 Wisconsin Academy of Sciences, Arts, and Letters. 
Hacker (38) who formerly (37) regarded the synaptic knot 
as natural is now “iriehr als friiher geneigt, auch den synap- 
tischen Knaliel fiir einen nicht ganz naiturlieh Zustand zu 
halten.” 
By far the greater proportion of cytologists however are of 
the opinion that the synaptic contraction is a normal stage in 
the heterotypic prophases. 
As to the mechanics of the synaptic contraction there is very 
little definite evidence. The shape of the knot as well as its 
location in reference to the nuclear membrane seem to indicate 
that it is due to some internal contraction and not simply a 
collapse of the chromatic nuclear content. Gravity, necessarily 
the important factor in producing a collapse, very evidently has 
nothing to do with the form and position of the synaptic knot, 
although Cardiff (1'4) has offered this explanation of the posi¬ 
tion of the knot. 
Babbs (78) conception of the nuclear organization, involving 
as it does the permanency of the chromosomes and the perman¬ 
ent connection of the chromosome with a center, should apply 
equally well to the movements of the spirem during synapsis as 
during the later phases of the mitosis. Evidences of such per¬ 
manent connection between spirem and the exterior are not 
lacking. 
In the ascus it has been shown by Harper (39) and Miss 
Sands (79) that there is a permanent connection of the spirem 
with the centrosome. Many investigators have figured fine 
fibers in attachment with the spirem during synapsis and in the 
following prophases. Among these are Earmer and Moore (23), 
Mottier (66) and Overton (73). Marquette’s (53, 54) work 
on Isoetes and Marsilia has demonstrated that in plants lacking 
centrosomes there may still be a polar organization of the 
cell. It is possible that in those forms whose nuclei lack per¬ 
manent centers there may still be a permanent connection of 
the chromatin with the cytoplasm. 
There is thus much to suggest that the phenomenon of synap¬ 
sis, as Well as the recovery from synapsis and the later move¬ 
ments of the spirem or its segments, previous to the formation 
