300 MONTGOMERY. [Vol. XV. 



la meme constitution filoide"; and similar nucleoli occur in the 

 Protista and in various cells of the Artliropoda. The " nucleole- 

 noyau " of the eggs of Cyfubulia and Lithobius has a fine 

 external membrane and a convoluted chromatin filament. In 

 the amitotic division of the capsular ovarial cells of Gryllotalpa 

 the nucleolus (formed of a central portion of chromatin and a 

 peripheral layer of plastin) divides first so that each daughter- 

 nucleus receives one nucleolus. But in the amitosis of the 

 intestinal cells of Aphrophora the " nucleoles plasmatiques " do 

 not divide ; and in the testicle cells (" metrocytes ") of Scolo- 

 pendra there is also a " nucleole plasmatique," and at the 

 commencement of the mitosis the "nucleole se liqu^fie pour 

 enrichir le caryoplasma," and is not to be found later. The 

 amitotic division of the fat cells of Geotnipes is introduced by 

 a division of the " nucleole-noyau." 



Frenzel ('85) studied the cells of the mid-gut in insects at 

 various stages of development. Bombyx dispar, larva : one 

 large nucleolus containing a vacuole, in which lies a small 

 spherical " Nucleollolus." Tachina, larva : here is one large 

 nucleolus, "mit kurzen zackigen Auslaufern. In seinem 

 Innern umschliesst er fast stets wenigstens einen, in der Regel 

 aber mehrere, etwa 6 bis 12, kugelige oder matt aussehende 

 Gebilde, welche nicht gerade den Eindruck von festeren 

 Korpern, sondern vielmehr von Vakuolen machen." In cylin- 

 der and gland cells of various insect larvae the nucleus is 

 filled with a homogeneous fluid, "in welche sowohl echte 

 Nukleolen, wie auch nucleolenartige Korper (' Keimflecken ' 

 oder 'Nukleolide') einerseits und andererseits zahlreiche ver- 

 schieden angeordnete sehr klein aber stets gleich grosse 

 Kornchen eingelagert sind, die hier ' Kerngranula ' oder 

 ' -granulationen ' heissen mogen." 



Leydig ('85) noticed in ganglion cells of Astacus a large, 

 spherical, granular nucleolus, in which is a large cavity ; this 

 nucleolar cavity stands in communication with that of the 

 nucleus itself. We read further : " Die Korper im Kern, die 

 man Nukleoli nennt, sind Bildungen verschiedener Art " ; some 

 arise out of the nodal points of the nuclear network, others out 

 of the " Kernplasma." 



