1896 | CERTAIN PYRENOMYCETOUS FUNGI 305 
there exists in the young ascus four nuclei which fuse in pairs 
to form a single primary nucleus. This nucleus divides in a 
true karyokinetic manner to furnish a nucleus for each spore. 
In the process of division (1) the chromatin collects in masses 
on the network; (2) the nucleolus becomes eccentric; (3) cen- 
trosomes with radiating strie appear; (4) the chromosomes 
arrange themselves in the equatorial plane, divide in halves and 
seek the poles; (5) the nuclear membrane is ruptured and the 
threads from pole to pole become very much elongated and 
parallel. The nucleolus meantime has gradually diminished 
and by the time the daughter nucleoli are formed it entirely 
disappears. The daughter nuclei attain normal size and struc- 
ture and undergo two further successive divisions, providing one 
nucleus for each spore. 
The foregoing summarizes briefly the work so far done along 
the lines of morphology and development in the higher fungi. 
As may be seen, the first two divisions of the subject (sexuality 
and structure of sporocarp) have received a comparatively large 
share of attention, but the conclusions even here are contradic- 
tory and unsatisfactory. Spore development and nuclear phe- 
nomena have been worked out to some extent in the Basidiomy- 
cetes and Discomycetes, Harper’s work on one genus stands 
alone for the Perisporiacez, while nothing at all has yet appeared 
for the sphariaceous Pyrenomycetes. Hence certain members 
of the last named group have been made the basis for the 
vestigations of which the results are here presented. 
METHODS. 
Growing —The material used for study was grown in artificial 
cultures and examined either in sections or by growing it upon 
glass slips immersed in nutrient media and transferring these 
— directly to the stage of the microscope. The latter method 
Served as a check on the former, since in sections the numerous 
a of the mycelium are likely to lead to erroneous con- 
ee el SOO, #5: pure cultures of the desired species were 
y ordinary dilution methods, the spores were sown I” 
