Notes . 
761 
viyces Pombe. The details of the process in the latter case seerp to 
be identical with those just described for Zygosaccharomyces. A pair 
of cells situated near together put out protuberances, which meet at 
their tips and fuse, spore-formation then following in the cells. The 
fused compound-cell usually retains the form of two cells united by 
a neck. In Schizo sac char omyces octosporus he finds that the method of 
fusion described by Schionning is not the most common. Usually a 
cell divides into two daughter-cells by a transverse wall. A small pro- 
tuberance is formed at the extremity of each of these daughter-cells. 
These protuberances fuse and form a canal of communication. The 
separating wall disappears and the canal enlarges, the single cell so 
formed becoming gradually oval, and spores are rapidly formed 
within. Very often the fusion of the cells is not complete, while in 
exceptional cases the cells become converted into asci directly without 
any fusion taking place. 
Since no mention is made of Hoflfmeister’s work nor of the case 
of conjugation in Zygosaccharomyces , Guilliermond has probably not 
yet seen the papers on those subjects. 
He has gone into the question of the behaviour of the nuclei very 
fully, and has published earlier this year two papers, which contain 
the results of his work on the Yeast nucleus, and which must therefore 
be considered before giving details of the nuclear actions which he 
observed during the process of conjugation. He found in Saccharo- 
myces cerevisiae and other species a nucleus of definite structure, 
consisting of nucleoplasm surrounded by a membrane and containing 
several granules, of which one, larger and more regular, is the 
nucleolus. The ‘ nuclear vacuole with chromatin granules ’ of Wager 
is, according to him, not nuclear in nature. He has studied the 
structure and development of these granules and the vacuoles in 
connexion with them in numerous species of Sacchar omyces and 
particularly in a Dematium , sp. The granules are not fatty in nature, 
nor apparently are they proteid, since they resist the action of pepsin. 
Nuclein solvents leave them untouched. They are, however, likely to 
be overlooked after such treatment, since their staining is rendered 
more difficult. They possess the characteristics of the ‘red grains’ of 
Biitschli. They are usually situated in the interior of vacuoles, and 
have their origin in connexion with that of the latter. At their first 
appearance they are very small, and are found in small hyaline spaces, 
probably the precursors of the vacuoles. These increase in size, and 
