MONTGOMERY. 
[Vol. XV. 
510 
beke (’97b), Mark (’ 77 ), Bancroft (’98). Compare also the follow¬ 
ing : Huie (’ 97 ), Van Bambeke (’ 97 ), Kosinski (’87, ’93), Mark 
(’77), Zimmermann (’96), Hodge (’94). I have found these bodies 
occurring in varying number, though most frequently absent, 
in the nucleoli of various cells, and they appeared to be merely 
loosened portions of the ground substance which had come to 
lie within a vacuole. Macfarlane and his pupil Mann have 
described nucleolini under the names “ endonucleolus ” and 
“ nucleolo-nucleus ” as occurring singly and with great con¬ 
stancy in certain plant cells, though Zacharias (’85) studied 
Macfarlane’s object ( Chara ) and makes no mention of any of 
these structures. Macfarlane ascribes the utmost importance 
to his “endonucleolus,” regarding it as the tropic center of the 
cell and as an important mechanical agent during nuclear 
division. Mann has not only described a most complex struc¬ 
ture of the nucleolus, such as no other observer has yet seen, 
but also has found fine fibrils radiating out from it, which he 
supposes to penetrate through the nuclear cavity. From my 
own observations, and in agreement with the majority of ob¬ 
servers, I can attach no particular morphological significance to 
the nucleolinus; it appears to be only a detached portion of 
the nucleolar ground substance, to be in most cases absent, 
and when present to vary greatly in regard to size, position, and 
number. It is undoubtedly the case that many structures 
which have been described as nucleolini are in reality minute 
vacuoles, which from their refrangibility appear to be granules; 
such is the case with the minute vacuoles of Polydora and 
Montagna when studied after the action of certain stains, and 
has been shown for other objects by Zimmermann and Huie, 
Lavdowsky found in the nucleolus a central vacuole, and in 
the latter a small granule, which he supposed to be “das noch 
in Entwicklung begriffene Centrosoma,” destined to finally 
pass out of the nucleolus; he was unable to determine how 
it does wander out of the nucleolus and become the centrosome, 
so that his suggestion has merely the value of a hypothesis. 
Van Bambeke describes the nucleolinus of the germinal spot 
of Amaurobins as “ doue d’un mouvement tres vif ” ; this 
interesting phenomenon certainly deserves investigation, though 
