504 ROBERT W. HEGNER 
ularly interesting, because they include a separation of the chro- 
matin of the mother cell into two masses. One of these masses 
of chromatin forms an ‘anello cromatico;’ the other gives rise to 
forty chromosomes which divide equally, half of each passing to 
each daughter cell. The chromatic ring remains undivided and 
becomes situated entirely in one of the daughter cells. At each 
of the three succeeding divisions the chromatic ring is segregated 
entirely in one cell; this cell is the oocyte, whereas the other 
fifteen which have a common origin with it are nurse cells. 
Since the publication of Giardina’s observations many ‘investi- 
gators have attempted to discover similar visible differentiations 
in the ovaries of other insects, but without much success. Thus 
Govaerts (’13) made detailed studies of beetles of the genera 
Carabus, Cicindela, and Trichisoma but was unable to find 
anything resembling the chromatic ring which occurs in Dytiscus. 
He found however that the spindle fibers (‘residu fusorial’) 
persist after the daughter cells are formed during the differential 
divisions, just as they do in Dytiscus, and that a definite polarity 
is marked by the position of these spindle remains. The con- 
clusion is reached that something more fundamental than the 
unequal division of chromatic elements is responsible for the 
differential divisions and decided in favor of a ‘polarite pre- 
differentielle.’ No explanation is offered, however, as to the 
origin of this polarization. 
A brief account of the oogenesis in carabid beetles has also 
been published by Kern (’12), who finds that during the differ- 
ential mitoses, the oocyte mother-cell may be distinguished by 
the presence of certain intracytoplasmic granules which he 
describes as follows: 
Befinden sich die Zellen der Zellrosetten in Teilung, so findet man 
mitunter in einer Zelle neben der Teilungsfigur eine Anhaéufung von 
fiirbbaren Koérnchen, dhnlich denjenigen, die in spateren Stadien in 
der jungen Eizelle im Cytoplasma gefunden werden. Es liegt nahe, 
an einen Diminutionsvorgang, ibnlich demjenigen, welchen Giardina 
bei Dytiscus beschrieben hat, oder auch an einen Vergleich mit 
den Ectosomen bei Cyclops zu denken; doch gelang es mir bisher 
nicht, alle Einzelheiten festzustellen. Die K6rnchen im Cytoplasma 
junger Hizellen werden nach und nach aufgelost. 
