STUDIES ON GERM CELLS 499 
because of this perfect distinctness that Paulcke (’01) failed to 
observe these rosettes. 
The evidence for the statement that all of the cells in a single 
rosette have descended from a single mother cell is irrefutable. 
In figure 2 the cells of the rosette to which the guide line (r) 
extends are grouped about a branching strand which stains 
black in iron hematoxylin. A similar rosette is shown enlarged 
in figure 3. One branch of the black strand extends into the 
cytoplasm of each cell. These strands consist of the spindle 
fibers remaining after previous mitotic divisions, and, as will 
be pointed out later, such strands are not uncommon in either 
the ovaries or the testes of insects. A section through one end 
of a rosette at right angles to that shown in figure 3 is illustrated 
in figure 4. The spindle remains form a sort of axis about which 
the strands from the most recent divisions are radially arranged. 
The entire rosette is therefore oblong and may be sectioned 
longitudinally or transversely. The number of cells in each of 
the rosettes figured is sixteen, indicating that four divisions had 
occurred since the oogonial mother cell was established. No 
evidence was obtained which indicated the presence of amitotis 
in these ovarioles, and very few mitotic division figures were 
observed. Those that were found were invariably restricted to 
the cells in single rosettes (fig. 5), thus indicating that the cells 
in a rosette divide synchronously. 
A ¢ritical examination of both the cytoplasm and nuclei of 
the cells in the rosettes failed to reveal any constant differences 
among the cells of any particular rosette. Giardina (’01) dis- 
covered a difference in the nuclei of certain rosette cells in the 
ovarioles of Dytiscus, and Kern (712) has reported a difference 
in the cytoplasm of similar cells in Carabus, but no such dis- 
tinguishing marks were found in the bee. This indicates that 
all of the cells at this stage in the oogenesis of the bee are prob- 
ably potentially alike. At any rate no visible differences were 
discovered in material fixed and stained so as to bring out to 
the best possible advantage both nuclear and cytoplasmic bodies. 
The rosette zone in the ovariole is followed by the zone of 
differentiation (fig. 1, d). Certain of the cells increase in size 
