04 Wisconsin Academy of Sciences, Arts, and Letters. 
From the lower portion of the spore, thus formed, a sterile cell 
is cut off containing two. nuclei. He does, not give details of 
this* division but from what he does say and from his figures, it 
is evident that he had seen something of the so called conjugate 
division but had failed to understand what he saw. In the 
same way he describes the young teleutospore of Puccima as 
containing two nuclei. It then becomes two 1 celled by the for¬ 
mation of a wall between these two nuclei. Each of these cells 
is thus at first uninucleated. This nucleus then divides. 
There is then a two celled teleutospore, each cell containing two 
nuclei. He regards it as probable that these two> nuclei in each 
cell fuse, as they were' later found close together. 
Dangeard and Sappin-Trouffy (4) observed that these two 
nuclei which are found in the young teleutospore and which, 
as a result of the conditions just, described, are widely sepa¬ 
rated in their nuclear parentage, fuse to form a single nucleus. 
They interpret this as a sexual fusion and consider that the 
ripe teleutospore cell is a fertilized egg. Sappin-Trouffy 
pointed out the mistake of Rosen by showing that the two nu¬ 
clei in the teleutospore are not formed by the division of a single 
nucleus.. Poirault and Raciborski attempt to. show that these 
two nuclei, dividing side by side, form a, single spindle and 
therefore at the time of division behave as a single nucleus. 
These authors describe quite fully the formation of the 
spores of Coleosporium. Poirault and Raciborski (3) de¬ 
scribed the aecidiospore of Peridermium Pini-acicolum and 
Sappin-Trouffy (1) describes the uredospore of Coleosporium 
senecionis. In Coloesporium it seems probable that the 
so called uredospore is really an aecidiospore. (Fig. 2). The 
mycelium which is to produce aecidiospores sends up perpen¬ 
dicular hyphal branches just beneath the epidermis. The api¬ 
cal cells of these branches contain two' nuclei, which usually lie 
side by side in the long axis of the cell. These nuclei then take 
an oblique position and finally a transverse position. They 
next divide, going simultaneously through the phases of divis¬ 
ion. Then the cell divides, two nuclei going to each cell. In 
these daughter cells the two nuclei come one from each of the 
mother nuclei of the mother cell so that the nuclei in each cell 
