210 EYES OF INSECTS. 
Mother, The rnotb of the silk worm 
is supposed to have six thousand lenses, 
that is, three thousand in each eye ; in a 
butterfly, they are estimated at seventeen 
thousand ; and in the eye of a small fly,^^ 
eight hundred have been actually counted 
by Leuwenhoek, a celebrated naturalist, 
who lived in the beginning of the last 
century. 
Lucy, How was it discovered, that 
each of these different lenses was a dis- 
tinct eye ? 
Mother, That indefatigable philoso- 
pher contrived, by using a microscope,, 
to look through one of them. 
Lucy. And could he see any thing ? . 
Mother, He distinctly saw the steeple 
of a church, which was seven hundred 
and fifty feet from the place where he 
sat. In looking also at the front of a 
house, he could distinguish the windows 
and doors, and could discern which of 
the windows were open. Thus, each 
lens may be considered as the object glass 
of a tiny telescope. 
