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MONTGOMERY. 
[Vol. XV. 
Held (’95) finds that in the ganglion cells of vertebrates, 
when stained with erythrosin followed by methylen blue, the 
nucleolus stains blue and the “ Nebennucleoli ” violet. 
Herrick (’95) found that the nucleolus of Homarus contains 
one large and several smaller vacuoles ; the gravitation of the 
nucleolus in the caryolymph, i.e., its movement to the lower 
side of the nucleus, may be post-mortem phenomena (at least I 
learned as much from Dr. Herrick during a brief conversation). 
Keuten (’95) investigated the nuclear division of Euglena 
viridis. In the nucleus there is an elongate body, the “Nucle- 
olo-Centrosoma,” which stains more intensely than any other 
portion of the nucleus. At the commencement of mitosis it 
elongates, “ und wahrend die Segmente [Chromosomen] bisher 
eine annahernd senkrechte Richtung zur Oberflache des Nucle- 
olo-Centrosomas eingenommen hatten, bilden sie jetzt einen 
spitzen Winkel mit demselben,” and gradually come to lie 
parallel to it. At this time the middle piece of the “ Nucleolo- 
Centrosoma” stains more lightly than its ends, so that these 
latter parts are sharply demarcated from it (with the stain of 
Heidenhain, namely, Bordeaux R. followed by haematoxylin). 
“In der folgenden Phase riicken die parallel zum Nucleolo- 
Centrosoma gelagerten Chromosomen von beiden Polenden her 
nach dem Aquator zu, so dass die Enden des Nucleolo-Cen- 
trosomes nunmehr frei in die Kernhohle hineinragen, wahrend 
die Chromosomen als breite aquatoriale Zone das Mittelstiickdes 
Nucleolo-Centrosomes umgeben.” Next, the nucleus assumes 
the form of a rotation ellipse, in the short axis of which the 
“Nucleolo-Centrosoma” lies. After the longitudinal splitting 
of the chromosomes, from three to five vacuoles appear in each 
end of the “ Nucleolo-Centrosoma ” ; then the latter structure 
elongates and breaks into two parts, while at the same time the 
long axis of the nucleus gradually changes so as to coincide 
with the long axis of the “ Nucleolo-Centrosoma,” and part of 
the chromosomes become grouped around the one end, the 
remainder around the other end, of the “Nucleolo-Centrosoma.” 
Keuten believes his “Nucleolo-Centrosoma” to be comparable 
to the nucleolus of Amoeba crystalligera (Schaudinn), to the 
“ Centralspindel ” in Diatomea (Lauterborn), and to the centro- 
