302 BOTANICAL GAZETTE | OCTOBER 
Sappin-Trouffy (4) describe certain nuclear fusions which they 
explain as sexual processes. No details of nuclear structure 
and division in these forms have as yet been described. 
In the Basidiomycetes the only process analogous to 
conjugation is the fusion of nuclei in the basidium before 
the formation of spores. Nuclear studies in this group have 
been more numerous and complete than elsewhere among the 
fungi. De Bary (1) in three species has observed the presence of 
nuclei in the basidium. Rosenvinge (6) has demonstrated the 
same in thirty-five species. Strasburger (7) has observed the 
nuclei in Agaricus and found that they divide. Wager (8) in 1893 
published the results of extensive nuclear studies upon Agaricus 
and Amanita, According to his statements, the nuclei of the 
basidia fuse in pairs before spore formation, and after this fusion 
Successive bipartitions of this fused nucleus occur to furnish 
nuclei for each of the four sterigmata. During division the 
nuclear membrane is gradually dissolved and the nucleolus and 
chromatin masses left free in the cytoplasm. The latter have 
previously arranged themselves in an equatorial plate. A spindle 
is now formed, at the poles of which are dark rounded bodies, 
probably centrosomes, but he fails to find any radiating strie. 
During the division the nucleolus disappears. After division 
of the chromosomes the spindle disappears and the daughter 
chromosomes at either pole fuse together and, he states; 
“apparently form the daughter nucleole.’? At the same time 
the linin network becomes more strongly differentiated, new 
membranes are formed, the daughter nuclei assume the size and 
appearance of the parent nucleus and are again ready to divide. 
In the Ascomycetes minute study becomes much ee 
difficult, the investigations are more meager and less reliable 
and the conclusions are more at variance. Of the generalizations 
made by De Bary (1) and others it is only necessary to call ae 
attention here to those on the sphzeriaceous Pyrenomycetes- 
Bary cites only Xylaria and Sordaria as having unmistal@® * 
sexual organs, and in these conjugation has not been wae 
In Xylaria the archicarp, he says, seems to disappeat before Hs 
