Life-cycle of Some FHymenopterous Insects 353 
are not directly fertilized, but the seminal fluid is stored up in the 
receptacle, and this supply, once received, must serve for all sub- 
sequent fertilizations. Dzierzon thought that the queen has 
the power of determining at will whether an egg is to become 
fertilized or not, and determines thereby the sex of the individual. 
He thought that all the eggs in the ovary are alike, and the sex 
of the individual is determined by the occurrence or absence of 
fertilization. 
The theory of Dzierzon has been much discussed, and while 
its main facts have been confirmed there have not been lacking 
those who have disputed one or another of its postulates. 
It was soon appreciated that the theory could be tested if the 
queen of one race is fecundated by the male of another race; 
for according to the theory the queens and workers that are 
produced by such a queen should be hybrids, but the males 
should belong to the pure maternal race. Thus ifa virgin Italian 
queen is put into a hive of German bees, lacking their own queen, 
the new queen may be fecundated bya German male. Her female 
offspring, queens and workers, will be hybrids; but her male 
offspring, the drones, will be pure Italians. Dzierzon himself 
found one instance that was an apparent exception, and so great 
was his confidence in this test that he gave up, for a time, his 
own theory, although later he appears to have returned to it 
from the confirmatory results of v. Berlepsch and v. Siebold. 
This hybridizing experiment has been a source of contention 
down to the present day, and well serves to illustrate how many 
dangers may lurk in even a comparatively simple experiment. 
Some of the objections to the theory may now be briefly con- 
sidered. It appears that in some cases the drones are like the 
hybrids, or even like the male, presumptively not their father, 
that fertilized the queen. Thus Perez found that after intro- 
ducing an Italian queen fertilized by a French drone into a 
French hive, she produced 300 drones of which 5 were pure Ital- 
ians, 83 pure French, and 66 were hybrids. The result proved, 
he thought, that the drones were hybrids. Similar cases have 
been described by other observers. The results seem to be 
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