244 A. B. MACALLUM. 
form of a circle or of a segment of a circle at either pole of the 
oval cell, and there was no relation between their size and that 
of the cell containing them, although they appeared to have 
some connection with the budding process, since he observed 
them undergoing transference to the protoplasm of the bud. 
What the nature of these granules is Raum does not say, but 
the results of his experiments would seem to indicate that they 
are not formed of nuclein, for on submitting the yeast-cells to 
digestion with an artificial gastric fluid at a temperature of 
40° C. for one or two days, and afterwards on washing with 
ether and alcohol, every trace of the granules had vanished. 
Nuclein is undoubtedly present in yeast-cells, and Raum 
prepared some of it from this source, which he mounted in 
egg-albumen on a cover-glass, and stained, first with methylene 
blue and afterwards with bismarck brown, when he found that 
the nuclein particles took a brownish stain while the albumen 
appeared light yellow, a reaction in marked contrast with that 
obtained in the granules of the hardened yeast-cells after the 
employment of the same staining methods. Raum appears to 
be doubtful concerning the existence of anything resembling a 
nucleus in the yeast-cell. 
The more recent observers who claim to have found a 
nucleus in the yeast-cell are Moller aud Janssens. The 
former! found in older yeast-cells a spherical corpuscle which 
he regards as a nucleus, but without a membrane or nucleolus. 
This changes its shape readily, and therefore its position in 
the cell varies. Owing to this property, it is capable of 
assuming a thread-like form when budding occurs, a portion 
of it being thus enabled to pass into the protoplasm of the 
bud through the narrow tube which connects the mother and 
daughter elements. The part in the latter eventually breaks 
off, and both portions become spherical. Janssens,? who used 
1 “Ueber den Zellkern und die Sporen der Hefe,” ‘Centralbl. fiir Bakt. 
und Parasitenkunde,’ vol. xii, 1892, p. 537; also “ Weitere Mittheilungen 
iiber den Zellkern und die Sprosse der Hefe,” ibid., 1893, vol. xiv, p. 358. 
2 « Beitrige zu der Frage iitber den Kern der Hefezelle,” ‘Centralbl. fiir 
Bakt. und Parasitenkunde,’ vol. xiii, 1893, p. 639. 
