IRON COMPOUNDS IN ANIMAL AND VEGETABLE CELLS. 243 
presence of these compounds in higher organisms. I have, 
however, endeavoured to solve it by the investigation of a few 
widely different forms, and the results now to be described 
show the presence of “ masked” iron compounds similar to 
those found in all the higher organisms. These forms com- 
prise: Saccharomyces cerevisix, 8. Ludwigii, Hy- 
phelia terrestris Fries,a leucosporous Agaricine, Cystopus 
candidus, and Aspergillus glaucus. 
The question of the occurrence of a nucleus in Saccha- 
romyces bears upon that relating to the presence of iron- 
containing chromatin-like substances in this genus ; and, con- 
sequently, it is necessary to give an account of the various 
observations that have been made on this subject. 
The earlier botanists, Nageli! and Schleiden,? claimed that 
they had found a nucleus in the yeast-cell, and the later 
observers, Schmitz,> Strasburger,* Zalewski,® and Zacharias,é 
have maintained that it exists, while Zimmerman’ speaks 
reservedly on the question. Raum’ found in yeast-cells which 
had been fixed on the cover-glass by heat or by solutions of 
corrosive sublimate, and stained, first with warm methylene- 
blue and then with bismarck brown, black spherical granules, 
varying in number from one to fifteen, in a more or less 
brown-tinted protoplasm. These were usually arranged in the 
1 «Zeit. fiir wiss. Botanik,’ vol. i, p. 45. Reference in Raum’s paper. 
> «Grundziige der wiss. Botanik,’ 1849, p. 207. Referred to by Raum. 
3 “ Untersuchungen iiber den Zellkern der Thallophyten,” ‘Sitzungsber. 
der Niederrhein, Gesell. fiir Natur- und Heilkunde zu Bonn,’ Sitzung. am 
4 Aug., 1879. 
4 «Das Botanische Practicum,’ p. 339, 1887. 
5 “On Spore Formation in Yeast Cells,” ‘Transactions of the Scientific 
Academy of Cracow’ (Polish), 1886. Abstract in ‘Bot. Centralbl.,’ vol. 
ZXVe po L. 
6 « Beitrage zur Kenntniss des Zellkerns und der Sexualzellen,” ‘ Bot. 
Zeitung,’ 1887, Nos. 18-24. 
7 “Die Morphologie und Physiologie der Pflanzenzelle,” Breslau, 1887, 
p. 25. Ihave not had access to this publication, and my attention was first 
called to it by a reference made by Raum. 
8 “ Zur Morphologie und Physiologie der Sprosspilze,” ‘ Zeit. fiir Hygiene,’ 
L891, vol.x, p. 1. 
