706 : THE AMERICAN NATURALIST. [Vor. XXXIX. 
Several papers have appeared on the structure of the yeast 
cell since Wager’s account of 1898. Marpmann (:02) and 
Feinberg (:02) described much simpler conditions than are 
reported by Wager, and recognize scarcely more than a deeply 
staining body which they term a nucleus. Hirschbruch (: 02) 
gives an extraordinary description, accompanied by diagram- 
matic figures, of a nuclear structure and a body, staining red 
and blue respectively, which are supposed to fuse previous to 
the development of a bud, but the account is so unsatisfactory 
as to merit little attention. Janssens (:03) reviews the work of 
these investigators and others in comparison with his earlier 
results (Janssens and Leblanc, '98). Guilliermond (:04) has 
published the most, recent paper presenting more completely his 
conclusions of an earlier investigation in 1902. ` 
Guilliermond's conclusions have some points of resemblance 
to those of Wager. He finds a nuclear vacuole containing a 
granular network believed to be chromatin and a nucleolar 
structure. The entire body seems to be a true nucleus, not dif- 
fering in its essentials from the nuclei of other fungi. Some- 
times all the material in the nucleus seems to be condensed into 
a central body, a sort of chromatin nucleolus (chromoblast) 
somewhat resembling a similar structure in Spirogyra. Guillier- 
mond figures the nucleus as constricting during the process of 
budding, one part passing into the daughter cell. His figures 
show clearly deeply stained material outside of the nuclear 
membrane in a position similar to that of Wager’s nucleolar 
body (nucleolus). 
These points of agreement seem to justify at least in part 
Wager’s account, but of course the peculiarities of both lead 
one to suspect that there are important features in the structure 
of the nucleus and in the events of nuclear division which have 
not been determined. It certainly seems probable that chroma- 
tin is present in definitely organized bodies (chromosomes) some- 
times within a vacuole and sometimes lying around a nucleolar 
structure. The latter also holds an intimate relation to the 
. chromatin, which is frequently true in higher plants. There are 
indications that a simple type of spindle is present at least in 
the nuclear divisions during spore formation. In view of 
