The Senses of the Lower Animals. 
306 
[July, 
high. At one point I noticed a sort of assembly, of about 
a dozen individuals, that appeared in consultation. Sud- 
denly one ant left the conclave, and ran with great speed up 
the perpendicular face of the cutting without stopping. It 
was followed by others, which, however, did not keep 
straight on like the first, but ran a short way, then returned, 
then again followed a little farther than the first time. 
They were evidently scenting the trail of the pioneer, and 
making it permanently recognisable. These ants followed 
the exa 6i line taken by the first one, though it was far out 
of sight. Wherever it had made a slight detour, they did 
so likewise. I scraped with my knife a small portion of the 
clay on the trail, and the ants were completely at fault for a 
time which way to go. Those ascending and those descend- 
ing stopped at the scraped portion, and made short circuits 
until they hit the scented trail again, when all their hesita- 
tion vanished, and they ran up and down it with the greatest 
confidence.” Mr. Belt further thinks that ants “ can com- 
municate the presence of danger, of booty, or other intelli- 
gence, to a distance, by the different intensity of the odours 
given off.” In this hypothesis of a scent-language addressed 
to the organs of smell, taking the place of a sound-language 
addressed to the organs of hearing, strange as it may seem 
at first glance, there is nothing impossible or even impro- 
bable. The language of man and of many other Vertebrates 
demands the power of producing at will sounds, joined to 
the faculty of recognising them ; in other words, the joint 
possession of vocal and auditory organs, In like manner, 
the language which Mr. Belt thus attributes to ants requires 
merely the power of producing odours, and of distinguishing 
them when produced. Now, one of the most striking pecu- 
liarities of inserts, as compared with vertebrate animals, is 
the variety and intensity of the odours which they emit, 
even as appreciable to our olfactory nerves. There are 
genera, and even species, which an experienced entomologist 
can recognise, even blindfold, by the smell alone. How 
distindt these scents must be to such sensitive organs as are 
evidently possessed by inserts will be understood from the 
fadts stated above. It appears also that in certain cases 
these odours can be emitted, suppressed, or varied at will. 
Here, therefore, are all the facilities needed for a scent- 
language. Our want of some standard for remembering 
and recording odours renders the study of this subjedt 
peculiarly difficult. 
Curiously enough, the notion has been lately taken up 
that insedts, after all, do not possess the sense of smell. 
