296 
DZIERZON THEORY 
RECENT EVIDENCE IN PROOF OF DZIERZON 
THEORY. 
Any reliable evidence either for or 
against Dzierzon’s theory, that the drones 
of the honeybee are produced from unfer¬ 
tilized eggs, is at the present time of more 
than usual interest to beekeepers. In one 
of the issues of the American Natural¬ 
ist, T. H. Morgan describes some experi¬ 
ments made by Newell at Houston, Tex., 
in mating Italian and Carniolan bees. 
When yellow virgin Italian queens were 
mated with grayish Carniolan drones, both 
the workers and queens which came from 
fertilized eggs were yellow, from which it 
was inferred that yellow is dominant over 
gray. The drones also were yellow like the 
Italian mother. Now this, too, might have 
been caused by the dominance of the mater¬ 
nal color (yellow) ; or, on the other hand, 
it might have been caused by the fact that 
in accordance with Dzierzon’s theory these 
drones inherited from the mother only,— 
that is, that the eggs that produced them 
were not fertilized by the drones. The ex¬ 
periment, therefore, as Morgan points out, 
is not decisive. 
The reciprocal experiment was, however, 
decisive. When gray Carniolan queens 
were crossed with yellow Italian drones, the 
workers and queens were yellow as before, 
due to the dominant yellow of the father. 
But the drones were gray like the gray 
Carniolan mother and the pure stock of 
Carniolan drones. That is, they inherited 
from the mother alone. Otherwise, they 
would have been yellow. This proves that 
they came from unfertilized eggs. Prof. 
Morgan characterizes these crosses as fur¬ 
nishing the long-sought evidence demon¬ 
strating that the drones inherit only the 
characters of their mother in accordance 
with Dzierzon’s theory. 
According to Fabre’s observations par¬ 
thenogenesis also occurs among the solitary 
bees in the genus Halictus. The males of 
this genus do not appear until fall. After 
mating with the females they fly about 
among the flowers for a week or so and 
then all perish, none surviving the winter. 
The fecundated females hibernate in their 
old nests, or in the crevices in stone walls, 
or other retreats. With the return of warm 
weather they reappear, dig new burrows, 
and provision their cells with little masses 
of pollen and honey, on each of which they 
lay an egg. From these eggs come only 
females, and at this season of the year 
there are no males of this genus in exist¬ 
ence with which they can mate. This first 
generation of females soon build new 
groups of cells, the daughters of a single 
mother extending the old nest, and all using 
the old entrance-tunnel in common. The 
eggs of these unimpregnated females give 
birth to both males and females; thus in 
the second generation both sexes are pro¬ 
duced by parthenogenesis. After mating 
the males die, and the females survive the 
winter and the cycle is repeated as before. 
Fabre sums up as follows: “The Halicti 
have two generations a year; one in the 
spring, issuing from the mothers who have 
lived thru the winter after being fecundated 
in the autumn; the other in the summer, 
the fruit of parthenogenesis; that is to say, 
of reproduction by the powers of the 
mother alone. Of the union of the two 
sexes females alone are born. Partheno¬ 
genesis gives birth at the same time to 
females and males.” 
