S8 Wisconsin Academy of Sciences , Arts and Letters. 
figures which have so far been given of synaptic stages show 
no conspicuous centering of the chromatin strands upon any 
particular region, although occasionally a nucleus has been fig¬ 
ured showing a rather conspicuous orientation of the strands 
upon a certain part of the nuclear membrane; for example, 
by Overton for Ilelleborus foetidus 8 * (in this case the nucleole 
is included in the synaptic mass but does not lie in contact 
with the nuclear membrane), and by Berghs for Narthecium 
ossifragumd In the latter case the strands are centered upon 
a nucleole lying at the periphery of the nucleus. But in other 
figures of the same plants given by these authors the nucleoles 
lie outside of the synaptic mass and the chromatin strands show 
a less regular course. In Lilium 7 which has been so extensively 
studied, 10 there seems to be little indication of an orientation 
of the strands upon any one region, nor is there any regularity 
in the position of the nucleole. In Marsilia quadrifolia the 
orientation of the chromatin strands during synapsis is appar¬ 
ently as definite and characteristic as in Phyllactinia or in any 
of the animal cells. 
The nuclear membrane also shows an interesting dissimilar¬ 
ity between its “polar” and “antipolar” sides. This differ¬ 
ence stands out especially well in preparations which are 
stained rather faintly. The nuclear membrane appears much 
heavier on the side of the nucleus turned away from the 
starch mass than on the side next to it. In some cases it al¬ 
most looks as if a close-fitting cap extending over one-third to 
two-thirds the surface of the nucleus were symmetrically placed 
opposite the synaptic mass over the otherwise thin nuclear 
membrane. If the preparation has a slight excess of the orange 
stain, this part continues to stain blue and stands out in con¬ 
trast to the otherwise largely yellow preparation. Whether there 
actually is a thickening of the nuclear membrane here is per¬ 
haps a question. In a normally stained preparation it is seen 
8 Overton, J. B.: Histologische Beitrage zur Vererbungsfrage. 
Jahrl. f. wiss. Bot., xlii (1906), PL VII, Pig. 46. 
a Berghs, J.: La formation des chromosomes heterotypiques dans 
la sporogenese vegetale. La Cellule, xxii, Fig. 17. 
io See the figures of Allen, C. E.: Jahrb. f. wiss. Bot., xlii (1906), 
PL II, and Ann. Bot., xix, Pl. VI. 
