1912] CURRENT LITERATURE 521 
ane and fuse as they near the apex. The fusion nucleus increases greatly 
size and forces the vacuoles, which had hitherto — a position between 
i nucleus and the end of the basidium, toward the periphery. Stages in this 
process are hard to follow because of the rapidity of ieee but finally 
the single nucleole comes to lie in a tangle of chromatin in an otherwise clear 
nucleus. This seeming synapsis leads to a spireme stage which must be of 
rather long duration because of the many found. Parallel anne are noted 
which become more conspicuous as the fibers shorten and segment, giving a 
characteristic diakinesis. At this stage the nuclear membrane has Seek 
but there is as yet no trace of spindle fibers. In the lower portion of the 
basidium there appears at this time a network of ak which finally partly 
surround the nuclear material, but which, however, seem to have nothing to do 
with the formation of the spindle. The long narrow spindle, seemingly of only 
one-half of which passed to either pole. No resting stage follows the division, 
the secondary spindles appearing at once, shorter, broader, and having two 
chromosomes at each pole when the process is completed. Four rather large 
nuclei are formed and gradually migrate toward the base of the basidium. 
Sterigmata develop and the nuclei become beak-shaped and pass into the 
developing spore and again divide.. In some instances it was found that the 
nuclei begin to divide while still in the basidium, the process being completed 
when the spore is reached. 
Kntep" finds in the mycelium from a single spore only one nucleus in each 
cell, and this condition persists even in cultures a year old. He finds in young 
cultures (3-4 weeks) that basidia are produced without the formation of a 
nuclei of the mycelium, but according to Kntep is never due to a fusion. Each 
contains a conspicuous nucleole and a dense tangle of chromatic material con- 
nected to the nuclear membrane by numerous strands. The nucleus increases 
in size with the growth of the basidium, the nuclear material becomes granu- 
lated, at times parallel threadlike portions are noted, the nucleole decreases.in 
size, and the dark-staining chromatic material becomes very much contracted. 
At this stage conspicuous double threads are observed. This stage, which very 
' much resembles synapsis, precedes the formation of a spireme, during which 
the nucleus migrates to the apex of the basidium, where follows a rapid con- 
traction of chromatic material accompanied by the disappearance of the 
nuclear membrane. KwNiep was able to count at this stage four masses of 
chromatin from which radiations extended into the cytoplasm, giving very 
77 Knrep, Hans, Ueber das Auftreten von Basidien im einkernigen Mycel von 
Armillaria mellea Fl. Dan. Zeitschr. Bot. 33381. 1911 
