o 



60 MONTGOMERY. [Vol. XV. 



Sala ('95), ovum of Ascaris : in the first maturation mitosis 

 the single nucleolus breaks into small pieces of various size, 

 which gradually become scattered throughout the nucleus ; 

 then they become smaller and spherical, and come to lie directly 

 under the nuclear membrane. These fragments may possibly 

 stand in a genetic connection with the corpuscles which are 

 subsequently found at each pole of the spindle. And since the 

 latter corpuscles may stand in some connection to a centrosome, 

 " es ist . . . nicht unmoglich, dass eine enge Beziehung besteht 

 zwischen der Auflosung des Nucleolus und dem Auftreten des 

 Centrosoma." 



Schloter ('95), gland and liver cells of Salamandra : in 

 the nuclei may be distinguished, besides the chromatin and 

 paralinin, red-staining spherical corpuscles, the larger of which 

 are regarded as plasmosomes. 



Sobotta ('95), ovum of Mus : in contradiction to the view of 

 Holl, the chromosomes are not derived from the nucleoli only, 

 but from the whole chromatic substance of the nucleus. 



van der Stricht ('95) observed in the larger ovarial eggs of 

 Amphiox2is that each contains a large nucleolus with an excen- 

 tric vacuole ; it disappears at the time of formation of the pole 

 spindle. 



Vejdovsky ('95a) found large, homogeneous nucleoli in the 

 yolk cells of ProrhyncJms hygrophihis, "die nicht die gewohn- 

 liche kugelige Gestalt bewahren, sondern immer in Theilung 

 begriffen sind. Man findet meist doppelte Kernkorperchen, 

 deren Halften durch eine ziemlich tiefe Furche von einander 

 getrennt sind und die eine centrale Hohlung erkennen lassen. 

 Nebstdem findet man in Drei- selbst Viertheilung begriffene 

 Kernkorperchen. , . . Ich glaube . . . , dass man es hier mit 

 einer Hypertrophic der normalen Kernkorperchen zu thun hat, 

 welche schliesslich zur Degeneration der Kerne fiihrt"; these 

 nucleoli occupy more than two-thirds of the space within the 

 nucleus. In the ovum the nucleolus is much smaller, and 

 shows a division into two parts ( Fig. 89), but here these two 

 parts are not of equal size. 



Vejdovsky ('95b) found in the egg of Botlirioplana a spherical 

 nucleolus, " mit einem Nucleolinus." 



