THENOGENESIS. 
151 
latrix are entirely absent. It is evident such eggs, 
if laid, can only produce drones, as they cannot be 
fertilised, and this is in fact found to be the case. 
The question may naturally be asked, why these 
workers lay, and why their ovaries are more deve- 
loped than those of other workers ? Leuckart dis- 
covered {^Bienenzeitung^ 1 ^ 55 ? P- 209) that the larva 
of a worker was weaned after it had left the egg 
three days, and as we have seen on page 120, 
the food underwent a change, whereas the queen 
larva received abundantly the same food during 
the whole of her existence, which he called royal 
jelly. He also found that it is exactly at the 
time of the change of the larval food that the 
female genital organs make their appearance, which 
will remain rudimentary or develop according to the 
food administered. If, therefore, weaning does not 
take place at the right time, any excess of royal food 
will develop the ovaries in proportion, and thus pro- 
duce a fertile worker, which cannot mate, and can 
consequently only lay eggs producing males. 
The discovery is attributed to Schirach (146) that 
if the bees lose a queen they are able to raise one from 
a worker larva, and for doing this they select one 
usually not more than three days old, when, by en- 
larging the cell and feeding more abundantly on 
special food, as we have described in Chapter xviii., 
the desired object is attained. 
In artificial queen-rearing, we have aUvays insisted 
on having queens started from the egg, so that they 
might have an abundance of proper food administered 
