224 
INSTINCT. 
Chap. VII. 
what work they could. If their presence proved useful 
to the species which had seized them—if it were more 
advantageous to this species to capture workers than to 
procreate them—the habit of collecting pupae originally 
for food might by natural selection be strengthened and 
rendered permanent for the very different purpose of 
raising slaves. When the instinct was once acquired, 
if carried out to a much less extent even than in our 
British F. sanguinea, which, as we have seen, is less 
aided by its slaves than the same species in Switzerland, 
I can see no difficulty in natural selection increasing and 
modifying the instinct—always supposing each modifi¬ 
cation to be of use to the species—until an ant was 
formed as abjectly dependent on its slaves as is the 
Formica rufescens. 
Cell-making instinct of the Hive-Bee ,—I will not here 
enter on minute details on this subject, but will merely 
give an outline of the conclusions at which I have arrived. 
He must be a dull man who can examine the exquisite 
structure of a comb, so beautifully adapted to its end, 
without enthusiastic admiration. We hear from mathe¬ 
maticians that bees have practically solved a recondite 
problem, and have made their cells of the proper shape 
to hold the greatest possible amount of honey, with the 
least possible consumption of precious wax in their con¬ 
struction. It has been remarked that a skilful work¬ 
man, with fitting tools and measures, would find it very 
difficult to make cells of wax of the true form, though 
this is perfectly effected by a crowd of bees working in 
a dark hive. Grant whatever instincts you please, and it 
seems at first quite inconceivable how they can make all 
the necessary angles and planes, or even perceive when 
they are correctly made. But the difficulty is not 
