206 Prof. von Siebold on the Law of 
bees, must also produce considerable excitement among the 
breeders of bees, as Landois in so many words completely de- 
nies the existence of the very peculiar parthenogenetic circum- 
stances under which the male bees are developed from the eggs. 
Landois appeals to his repeatedly successful experiments by 
which he thinks it is proved that all the eggs laid by a normal 
queen are fertilized by her, that in consequence of this ferti- 
lization the development of the larvee in the eggs takes place, 
and, further, that these larvee when just hatched from the egg 
do not yet possess any definite indications of sex. The sex 
of bees is rather [according to him] only fixed as male or fe- 
male by the difference of nourishment taken from without, 
according as the workers furnish drone-food to those larvee in 
the drone-cells, or worker-food to those in the worker-cells. 
Landois transferred the bottom of a drone-cell, furnished 
with an egg, into a worker-cell, and vice versé the egg-bear- 
ing bottom of a worker-eell into a drone-cell; and by this means 
from the egg destined by the queen to become a worker, the 
larva from which in consequence of this transfer was nourished 
with drone-food, he obtained a drone, whilst from the egg 
destined by the queen to become a drone, the larva of which 
in consequence of a similar substitution was brought up on 
worker-food, a worker was produced. 
Whether no error or illusion can occur in these experiments 
must be decided by practised and experienced bee-keepers, to 
whom I particularly recommend the repetition of this ex- 
periment. For my part I can only appeal here to those 
results which are to be obtained by anatomical and micro- 
scopic investigations of the larve of insects in course of de- 
velopment within the egg. Taking these into consideration, 
I feel compelled to express the greatest doubt as to the cor- 
rectness of the new theory set up by Landois. 
From the very careful investigations of various reliable 
observers in the domain of the developmental history of 
insects, we know that, even in the egg, simultaneously with 
the development of the different systems of organs of an 
insect-larva, the sexual organs also begin to be formed, and 
even become differentiated to such a degree that in a larva 
which has just escaped from the egg-shell we are already able 
to distinguish the male or female sex from the difference in 
form of the first rudiments of the inner reproductive organs. 
Herold, the well-known insect-anatomist, obtained the 
following results from his accurate investigations of the de- 
velopment of the cabbage-butterfly* :—The organs which 
* See his ‘ Entwickelungsgeschichte der Schmetterlinge,’ Kassel und 
Marburg, 1815, p. 1. 
