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MONTGOMERY. 
[Vol. XV. 
dicken Ring oder ein dickwandiges hohles Kiigelchen darzu- 
stellen scheint while in other cases it may be a simple spot, 
or may be wholly absent. “Aus meinen Beobachtungen an 
alien Pflanzen, die eine vollstandige Verfolgung des ganzen 
Bildungsprocesses erlaubten, geht hervor, dass dieser kleine 
Korper selbst friiher sich bildet, als der Cytoblast [Nucleus].” 
Macfarlane (’ 81 ) examined various plant cells, in all of which 
he found one or several bodies (“ nucleolo-nuclei ”) within the 
nucleolus. The nucleolus of Spirogyra has a distinct membrane, 
which disappears at the period of the nucleolar division ; the 
karyokinesis results in the formation of a “nuclear barrel,” at 
each end of which is a mass of nucleoplasm, these two masses 
being connected by fibers with the nucleolus which lies between 
them. The nucleolus then divides, preceded by a division of 
the nucleolo-nucleus, so that each daughter-nucleolus receives 
a daughter nucleolo-nucleus, and the daughter-nucleoli then 
wander apart to the nearest masses of nucleoplasm, “ as they 
retreat from each other they drive the polar masses before them, 
thereby elongating the nuclear barrel. . . . The nucleoli at 
length advance to the polar masses and bury themselves in 
the nucleoplasm of these.” From these and numerous other 
observations, Macfarlane concludes : “that the nucleolus, or 
more probably the nucleolo-nucleus, is the center of germinal 
activity, and that as we pass outwards to the periphery of the 
cell, this reproductive activity becomes less and less. In no 
other way, to my mind, can the number of nucleoli and nucleolo- 
nuclei at different ages in the cells of any plant be explained.” 
Strasburger (’ 82 a) gives reviews of previous observations on 
the chemical constituency of nucleoli. 
Strasburger (’ 82 b) studied nuclear division in various plant 
cells ( Fritillaria , Lilium, Hemerocallis , Tradescantia , Galanthus , 
Dicotyledons). “ Pollenmutterzelle ” of Fritillaria : between 
the nucleus and its membrane collects a homogeneous, refrac¬ 
tive, lens-shaped mass of substance; “ sie geht nicht unmittelbar 
aus den Kernkorperchen hervor, die ja schon auf vorausgehenden 
Stadien verschwunden waren, vielmehr reprasentirt sie, allem 
Anschein nach, ein Secret”; this body he terms “ Secretkor- 
perchen.” At first it stains deeply with methylen green ; but 
