50 THE HUMBLE-BEE I 
as I once noticed in a nest of B. terrestris. A few 
males are often produced with the later broods of 
workers, especially if the queen is not prolific, but 
workers are seldom produced with the males and 
queens, and such as do appear have probably failed 
to develop into queens through insufficient feeding. 
I have never known a queen to be produced among 
the regular batches of workers, but in some of my 
nests that I fed liberally large workers like those 
that are produced in the later broods were produced 
in the early broods. It seems, therefore, that an 
abundant supply of food is not sufficient to make a 
female larva develop into a queen, but that it may 
also be necessary for the larva to be from an egg 
that has been laid late in the queen’s life. Also the 
possibility that the development of a queen instead 
of a worker is the result of a slight differentiation in 
the food given to the larva must not be precluded. 
With the honey-bee, if the female larva is fed entirely 
on ‘‘royal jelly,” a rich milky food prepared in the 
chyle stomach of the bee, it develops into a queen ; 
but if it is weaned on the third day, and thereafter 
has honey added to its food, it becomes a worker. 
With the humble-bee, although no such differentia- 
tion in feeding is observable, and the queen larva 
appears to be fed like the worker larva on a gruel 
of honey and pollen, prepared in the honey-sac, it is 
not improbable that the composition of this food 
is slightly altered, when the colony has reached a 
certain stage, by, for instance, a greater activity in 
some of the salivary glands, of which no less than 
