336 BOTANICAL GAZETTE [NOVEMBER 
dark like the chromosomes at the time of division. Again itis 
possible that the chromatin had left the linin thread and col- 
lected in the above manner before the material was fixed. Or 
perhaps the reagents caused such a change in the chromatin. 
The investigation of fresh material alone can decide whether the 
process is normal or artificial. 
A remarkable change has also taken place in the chromatin 
thread. Before synapsis it was a network containing very large 
irregular granules, now it is a spirem with the granules much 
reduced in size and more uniform. For the most part they are 
but slightly broader than the scarcely thickened linin. These 
above mentioned peculiarities were found not in one case alone, 
but in a great many preparations, in fact in every preparation 
that contained the right stage. 
Synapsis has now been found in many plants, in all of which 
it always seems to be a natural condition, and it is quite proba- 
ble that it will prove to be a universal phenomenon, occurring a 
a certain period previous to each heterotypic division. Besides 
this, it has now been shown to occur in at least a few animals. 
Among plants it has been found in the Liliacea by Strasburger, 
Sargant, and others; in the Hepaticae by Farmer; and in Pota- 
mogeton and Acorus by the writer, in addition to several other 
‘plants, the studies on which have not yet been published. There 
now seems to be little doubt that the condition is a natural - 
for the following reasons. It may be found in the fresh mate 
rial, at least in Convallaria and Lilium. Moreover, it always 
occurs at the same stage in the development of the anther. 
Various structural changes in the chromatin thread always 
accompany it. In addition to this, many preparations show 1 
the mass may be deposited at any side of the nuclear cavity 
without reference to its position in the anther. 
Considerable uncertainty has always existe 
synapsis really is. The term was introduced by Moo 
year 1895, but the description was so brief that it is s° 
and plants 
das to just what 
re? in the 
Essential similarity of the chromosome reduction in animals 
Annals of Botany 9: 435. 1895. 
