32 Wisconsin Academy of Sciences, Arts, and Letters. 
that the chromosomes after a longitudinal splitting are pulled 
apart at the center and move to the poles. The second division 
is similar to the first. The four centrosomes remain at the 
summit of the basidium while the nuclei move to the center or 
base of the basidium. boon a sterigma is formed above each 
eentrosome, and fibres appear extending from the centrosome 
to the nuclei which now move to the summit, probably through 
the influence of these fibres. 
Two notes of Maire’s (16 & 17) in the Comptes Eendus report 
that the last two or three cells of the ascogenous hyphae of 
Pustularia vesiculosa, Galactinia succosa and Acetabula acetab- 
ulum are binucleated. The ascus like the basidium is the last 
of a series of binucleated cells. In order that such a comparison 
should have any value we must know how the ascogenous hyphae 
originate. 
In Hypochnus Harper (12) was able to trace a series of bi¬ 
nucleated cells from the hymenium to the mycelium in the sub¬ 
stratum. The mycelium did not form dense wefts or strands but 
spread through the decaying w r ood where it could be readily 
studied. The cells were regularly binucleated. The stages of 
nuclear fusion and division were similar to those described by 
Wager. At the equatorial plate stage the chromosomes were 
distinct and at least six or eight in number. 
The origin of the binucleated cells was not determined by 
these observers. Maire states that the two nuclei in the spore 
of Coprinus radiatus pass into the germ tube and a cross wall 
may or may not be formed between them. The mycelium is 
then of two types, the one apoeytic, the other cellular. The 
cells of the latter are uninucleated. He did not observe the 
transition from these stages to the binucleated condition found 
in the young carpophore. 
In a preliminary notice Blackman (2) has given a brief ac¬ 
count of the life history of two of the Uredineae. He finds that 
the spermatia do not have the structure of conidia but of male 
cells; a thin wall, no reserve material, a very large nucleus with 
no nucleolus and cytoplasm greatly reduced in amount. He 
also studied in detail the development of the aecidium of Phrag - 
midium violaccum. The aecidium arises as a layer of uninu- 
