Notes. 
762 
fuse together to form a large vacuole or vacuoles, while the granules 
also increase in size by fusion. The fine granules of Wager, which 
are contained in vacuoles, and which the latter author considered as 
nuclear, are shown to be identical in nature with the larger granules, 
which he considered as proteid. Dealing more particularly with the 
spore-formation in S. Ludwigii , a small nucleus with no observable 
structure is found in young vigorous cells in connexion with a vacuole 
containing numerous small granules, the ‘ red grains ' of Biitschli. 
Later, one or two more vacuoles containing glycogen appear at the 
poles of the cell. In the first stages of sporulation each of these 
divides, until the protoplasm appears to be entirely filled with small 
vacuoles separated by very fine meshes of protoplasm. The glycogen 
vacuoles and the vacuoles containing ‘ red grains ’ can be distinguished. 
Later the vacuoles containing ‘ red grains ’ change in appearance and 
the granules diminish in number and size, the vacuoles themselves 
then staining a uniform pale-red colour with those stains which give 
the ‘ red grains’ their characteristic red tint (haematoxylin, gentian violet, 
&c.). This colouration of the vacuoles is explained by the solution of 
the granules, since it never occurs at other times. At this stage the 
nucleus divides into two daughter-nuclei, which travel to either end 
of the cell and divide again. The division is intermediate between 
direct division and karyokinesis. Each of these nuclei becomes the 
basis of a spore, which is formed by the condensation of the proto- 
plasm around a nucleus. The epiplasm contains a substance that 
stains uniformly red, when the spores are very young, but this gradually 
disappears as the spores ripen. On account of these facts Guillier- 
mond regards the ‘ red grains 5 as reserve material, which is used up in 
spore-formation. 
Returning now to his account of the nuclear behaviour of S. octo- 
sporus during spore-formation, he states that the nucleus of this form 
consists of a deeply staining nucleolus surrounded by non-staining 
nucleoplasm with traces of a limiting membrane. It is in the 
neighbourhood of small vacuoles or one large vacuole containing 
‘red grains/ The nuclei in the cells about to conjugate are situated 
close to the point of fusion. When the wall disappears the two 
nuclei fuse. The fused nucleus soon divides into two daughter- 
nuclei, which travel into the cells and take part in spore-formation 
divisions. The ‘ red grains ’ disappear at the moment of fusion. 
Similar phenomena are observed in A. Pombe. 
