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MONTGOMERY. 
[Vol. XV. 
of the daughter-nuclei retained the original nucleolus, in the 
other a new nucleolus soon appeared, first in the form of a 
granular mass. 
In the paper by Balbiani (’ 64 ) movements of nucleoli are 
described for the first time, and these observations were made 
upon the living eggs. The first kinds of movements which he 
distinguishes are exhibited by the eggs of spiders : “ ces 
mouvements de la tache germinative sont caracterises par la 
production de prolongements transparents ayant presque tou- 
jours la forme de lobes arrondis qui s’allongent et se retractent 
alternativement.” The second kind of movements is shown 
in the egg of Phalangium , where there is a single large, 
spherical nucleolus, which appears spongy, owing to the pres¬ 
ence of a number of vacuoles, some of which “ s’el&vent plus 
ou moins au dessus de la surface en soulevant sous forme 
d’une ampoule la couche la plus externe de la substance du 
corpuscule. . . . Lorsqu’un porte son attention sur une de ces 
v^sicules superficielles, on ne tarde generalement pas a la voir 
grossir insensiblement, en meme temps que la couche de sub¬ 
stance qui forme sa paroi exterieure se souleve en s’amincis- 
sant de plus et plus ; puis, assez brusquement, cette paroi se 
rompt comme sous la pression d’un liquide interieur, et ses 
bords se retractent vers la base adherente de l’ampoule qui se 
trouve ainsi transformee en une petite cupule ou excavation 
superficielle, . . . et bientot il ne reste plus aucune trace de 
l’ampoule ni de F excavation qui lui a succddd.” All the periph¬ 
eral vacuoles discharge themselves thus in succession, while 
at the same time the smaller central vacuoles increase in size 
and wander towards the periphery to take the place of the 
preceding. Balbiani compares these movements to those of 
the contractile vacuoles of the Rhizopoda , but notes this dif¬ 
ference : in the latter forms the vacuole always forms itself 
at the same place again. In the eggs of Geophilus and of 
Helix pomatia he finds that the vacuole discharges through a 
small orifice. 
Balbiani (’ 65 b) describes some remarkable structures in ger¬ 
minal vesicles, all studied in life. In Geophilus longicornis 
there is an external infundibular canal extending from the sur- 
