' STUDIES ON GERM CELLS 505 
The origin of these granules was not determined, and although 
Kern is inclined to consider them similar to the chromatic-ring 
substance in Dytiscus, there is a possibility that they may be 
mitochondrial in nature or may consist of some other cytoplasmic 
material. 
The presence of intercellular bridges is important, since it 
makes it possible to determine the relationship of the groups of 
cells in the ovarioles. But in the queen bee these bridges do not 
persist to any considerable extent after the zone of differentiation 
has been reached. Here, however, as shown in figures 7 to 12, 
there are well defined rings between the cells which indicate their 
relationship. It might be argued that these rings may arise 
where two cells happen to come into contact, if it were not for 
the fact that all stages between the fully developed bridges and 
the presence of clearly defined rings have been observed. These 
are no doubt the persisting mid-bodies or ‘Zwischenkorper’ 
which remain between the cells after division. They have been 
noted especially by Giardina (’01) in Dytiscus; by Marshall 
(07) in Polistes; by Kern (12) in Carabus; and by Maziarski 
(13) in Vespa. 
Summary of Part I. 1. Four rather definite regions may be 
recognized in the ovariole of the queen honey bee (fig. 1): (a) 
the terminal filament; (b) a rosette region; (c) a zone of differ- 
entiation; and (d) the posterior part in which the oocytes are 
arranged in a linear series and separated from each other by 
groups of nurse cells. 
_ 2. The rosette region is filled with rosette-like groups of cells, 
each group consisting of the descendants of a single mother 
oogonium. The cells of a rosette are united by strands which 
are the persisting spindle fibers from earlier mitoses (fig. 3). 
The cells in a rosette divide synchronously (fig. 5). 
3. Oocytes and nurse cells are both derived from the oogonia. 
Their differentiation occurs in the zone of differentiation (fig. 1, d). 
One or more cells of each rosette enlarges and becomes an oocyte, 
whereas the others retain more of their earlier characteristics and 
become nurse cells. Although the strands which connected the 
cells in a rosette disappear, the descendants of a single oogonium 
