BEE MANUAL. 65 
No wonder that people were slow to accept this wonderful | 
doctrine. Von Berlepsch, in his exposition of the Dzierzon 
Theory, says :— 
“From time immemorial naturalists have regarded as universally 
true the doctrine that no living creature can be developed from the egg 
of a female without male impregnation. And when occasionally 
exceptional cases were adduced the men of science treated the state- 
ments with contempt, or endeavoured to impugn their force or 
validity by assuming that the observers were either incompetent or 
careless.” 
Dr. Dzierzon’s discoveries accordingly were received with 
incredulity and sometimes with derision ; but magna est veritas, 
et prevalebit / Dr. Dzierzon was assisted in proving his case 
by such scientists as Professors Leuckart and Von Siebold of 
Munich, and by the Baron von Berlepsch, the author of the 
celebrated ‘‘ Apistical Letters.” 
Von Siebold ‘‘demonstrated clearly, that not only do living larve 
occasionally issue from a portion of the unimpregnated eggs of the 
silkworm, and develop as moths—some male, others female ; but that 
in various species of butterflies the virgin females regularly lay eggs 
which, not partially only and occasionally, but uniformly and without 
exception, produce females.” 
Prof. Leuckart subsequently noticed a still greater number of 
exceptions, and says :— 
‘There can be no doubt that parthenogenesis exists far more exten- 
sively among insects than is now known or anticipated.” 
And Von Berlepsch adds :— 
‘This exception is found also among bees; with this difference, 
however, that among them al/ the eggs which remain unimpregnated 
invariably develop as males, and those which are impregnated invaria- 
bly develop as females, and that the impregnation of the egg determines 
its feminine sexuality. Consequently, in the case of bees, not only is 
every egg susceptible of development, though unimpregnated, but 
masculinity pre-exists therein, which (marvellous indeed !) is trans- 
formed into feminity by impregnation with the male sperm.” 
THE DZIERZON THEORY. 
Space will not admit of going into the details of observations 
and experiments by which the case has been proved. I shall 
only add the thirteen “ propositions” of the Dzierzon theory, 
F 
