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POPULAR SCIENCE REVIEW. 
Jlavus behaves as above described, but Formica fusca is much milder and 
more courteous in its demeanour towards strangers. Some of the experi- 
ments seem to show that the sense of sight is not very acute in certain 
species of ants. Thus, food was placed a few inches from the nest on a 
glass slip, the straight road to and from which was soon learned, but when 
the food was shifted only a short distance from its original position, the 
same individual ants wandered about in a circuitous path for several 
minutes and sometimes for half an hour, before discovering the new locality 
of the food. Sir John Lubbock confirms the statements of former writers 
as to slavery being a regular institution with some genera of ants, and states 
that the Amazon ants ( Polyergus mfescens ) absolutely require a slave at- 
tendant to clean and feed them. Some of his experiments seemed to prove 
that these aristocratic ants would rather die than help themselves. The 
author also referred to certain parasites on ants and in ants’ nests. 
