520 ROBERT W. HEGNER : 
diminution process also seems probable. Each secondary 
nucleus contains masses of chromatin and in every way resembles 
a true nucleus, but, as in other cases of diminution, this chromatin 
and the other contents of the secondary nuclei are lost in the 
general egg substance. The elimination of this material simply 
occurs in these species at an earlier stage than in the oocytes of 
other animals. 
The function and fate of the secondary nuclei cannot be stated 
with any degree of certainty. We have seen that they cease to 
form a compact group in the older oocytes and become distrib- 
uted throughout the egg, especially near the periphery (figs. 37 
and 39). Later they undergo a process which appears to be 
degenerative, and, according to those who have studied later 
stages, finally disappear altogether. The writer suggested a 
few years ago (Hegner ’09) that secondary nuclei of this sort 
might migrate to the posterior pole and take part in the formation 
of the germ-line-determinants, but thus far no actual evidence 
that this occurs has been obtained. Marshall (07) has ex- 
pressed the opinion that they may make the substances pro- 
vided by the nurse cells available for the oocyte. It also is 
possible, as Loyez claims, that these secondary nuclei may have 
some function in the formation of yolk. 
Summary of Part II. 1. The ovarioles of Camponotus con- ~ 
sist of four distinct regions (fig. 138), (a) a terminal filament, (b) 
a terminal chamber, (c) a zone of growth free from bacteria-like 
rods, and (d) the posterior part in which the oocytes are arranged 
in a linear series, are accompanied by nurse cells, and are sur- 
rounded and later invaded by the bacteria-like bodies. 
2. The bacteria-like rods occupy definite regions of the ovariole. 
They are absent entirely from the terminal filament, terminal 
chamber and first zone of growth. In the rest of the ovariole 
they occur everywhere except in the nurse cells (fig. 25). The 
oocyte is at first free from them (fig. 25) but later is invaded 
(fig. 26) and almost completely filled with them (fig. 29). The 
rods are arranged at first in bundles (figs. 25, 29), but later be- 
come scattered (figs. 35, 36). As the oocyte increases in size and 
