102 PERFECT SOCIETIES OF INSECTS. 
that, if they wish to emigrate, they will construct a living 
bridge in this manner :—One individual first fixes itself 
to a piece of wood by means of its Jaws, and remains sta- 
tionary; with this a second connects itself; a third takes 
hold of the second, and a fourth of the third, and so on, 
till a long connected line is formed fastened at one ex- 
tremity, which floats exposed to the wind, till the other 
end is blown over so as to fix itself to the opposite side 
of the stream, when the rest of the colony pass over upon 
it, as a bridge*. This is the process, as far as I can 
collect it from her imperfect account:—as she is not 
always very correct in her statements, I regarded this as 
altogether fabulous, till I met with the following history 
of a similar proceeding in De Azara, which induces me 
to give more credit to it. 
He tells us, that in low districts in South America, 
that are exposed to inundations, conical hills of earth 
may be observed, about three feet high, and very near 
to each other, which are inhabited by a little black ant. 
When an inundation takes place, they are heaped toge- 
ther out of the nest into a circular mass, about a foot in 
diameter and four fingers in depth. Thus they remain 
floating upon the water while the inundation continues. 
One of the sides of the mass which they form is attached 
to some sprig of grass, or piece of wood; and when the 
waters are retired, they return to their habitation. When 
they wish to pass from one plant to another, they may 
often be seen formed into a bridge, of two palms length, 
and of the breadth of a finger, which has no other sup- 
* Insect. Surinam. p. 18. Jn her plate the ants are represented so 
connected. 
