No. 2.] COMPARATIVE CYTOLOGICAL STUDIES. 351 
" minute nucleolar granules ” which were present in early stages. 
In contradiction to the view of Scharff (’88) he finds that no 
nucleoli wander out of the nucleus to form yolk globules. 
Delage (’95) opposes the view that the nucleoli and the 
centrosomes are genetically related (as against the theory of 
Julin (’93 b) and Wasielevsky). 
Galeotti (’95), embryonal cells of Triton and Spelerpes (fixa¬ 
tion in Hermann’s fluid with chloride of palladium substituted 
for chloride of platinum ; stained for five minutes in sat. sol. 
acid fuchsine in aniline water at 6o° C., then stained in 
sol. methylen green in equal parts of water and alcohol for three 
or four minutes): “ Auf diese Weise erhalt man roth gefarbt 
die Kornchen des Cytoplasma und alle Elemente des Kerns mit 
Ausnahme des Nucleolus . . . ; gelblichgriin erscheint der 
protoplasmatische Grund der Zelle und lebhaft grim die baso- 
philen Granulationen.” In the pancreas cells of Spelerpes the 
green-stained nucleolus passes out of the nucleus and persists 
as “ Nebenkern,” which in the cytoplasm seems to increase by 
continued division ; and from this he concludes “ dass der 
Nucleolus ein endonucleares Arbeitsprodukt des Kernes ist, 
bestimmt aus der Kernmembran auszutreten und im Cytoplasma 
so umgeandert zu werden, dass er in Secretionsprodukte umge- 
wandelt wird.” 
Hacker (’95) first describes the nucleolar relations in the eggs 
of Canthocamptns , and then gives expression to general views, 
based on his numerous previous observations, in regard to the 
nature of nucleoli. Canthocamptns staphylinus : in the smallest 
eggs there is one large nucleolus, which increases in size, but not 
to same relative extent as does the nucleus itself; subsequently 
vacuoles arise in it, one of which becomes a “ Hauptvacuole ”; 
smaller “ Kernkorper ” appear first when the chromatin elements 
commence to thicken ; “ wenn endlich die Kernsubstanz auf 
das Minimum ihres Volumens zusammengedrangt ist, so fehlt 
in der Regel jede Spur von nucleolarer Substanz.” Then 
follows his general conclusions in regard to the physiology and 
structure of the nucleoli : “ Die Nucleolen sind nach meiner 
Ansicht im allgemeinen als nicht strukturirte Gebilde aufzu- 
fassen. . . . Sie stellen als solche ... ein Abspaltungsprodukt, 
