104 FECUNDATION OF ANTS. 
observed in the meadows. To eftect this, 
I had only to walk slowly, the swarm by 
which I was surrounded following and 
accompanying me in all my movements, 
which I attribute either to my drawing 
after me the column of air in which they 
were flying, or to their regarding me as 
the base above which they were ele- 
vated, and, therefore, not aware of their 
removing from the point of departure. [ 
have never witnessed any of those ex- 
tensive swarms, of which M. Gleditsch 
has given us an account, in the Memoirs 
of the Academy of Berlin. ‘ He ob- 
served,” he says, *‘ an immense swarm 
of ants, which, viewed at a distance, 
produced an effect very much resembling 
an aurora borealis, when, from the bor- 
der of the cloud, appear by jets several 
columns of flame and vapour, attended 
with a variety of luminous rays and lines, 
orming no unapt resemblance to forked 
lightning, although destitute of its bril- 
liancy. Columns of ants, but less dis- 
tinct, were seen moving here and there, 
with inexpressible swiftness, continually 
