Insects. 9075 
poses, what has been observed of their resources under such circum- 
stances? Sometimes, if the stream is somewhat rapid, they form a 
floating chain, which, moving to and fro on the surface of the water, 
at length touches the opposite bank. I may record another contrivance 
adopted when a pond of still water interrupts their march: in such a 
case they have been observed to cluster together in masses, forming 
balls of ants, and in this condition they float on the water, and are 
wafted to the opposite shore. The late Mr. Foxcroft saw a number of 
these ant-balls floating across a pond, one of which he secured and 
placed in my hands; it proved to be the rare species Anomma Bur- 
meisteri. Do these expedients on the part of the ants exhibit no ray 
of intelligence? Are they nothing more than the irresistible actions 
of irresponsible agents ? 
One further illustration, and I leave it to others to show that all the 
instances advanced prove nothing in support of my own opinion. 
There is a burrow in that gate-post, constructed with infinite labour 
last summer by Osmia aurulenta; it now contains a few males and 
four females, all matured, and each is gifted with the power capable 
in every respect of performing every act necessary for the attainment 
of the ultimate purpose of her economy. One of the females issues 
from the burrow; like her parent before her, she excavates a burrow 
in the gate-post; this is the work of days of almost unremitted labour. 
A second bee takes flight, and, at some little distance, alights upon a 
sunny bank of compact fine sand; such a bank is admirably adapted 
to her purposes; she at once commences to excavate ; her task is 
light in comparison with that of her sister’s that we left labouring at 
the gate-post, and in half the time occupied by the first, the second 
has completed her task. 
Let us now attend to the third bee that is on the wing: passing the 
sunny bank, she makes her way, at length alighting on the thatch of 
an out-house; the thatch is composed of straw, twigs and reeds; 
amongst the Jatter is one the tube of which is exactly adapted for the 
nest-burrow of a bee; the Osmia observes this, and at once selects it 
for that purpose. 
The fourth bee is buzzing about some tufts of grass, flying here and 
there apparently without any very settled purpose, but she alights on 
a stem of grass, at the foot of which lies a snail-shell; now the whorl 
of this shell is very different in construction to the straight tube in the 
post, sand-bank or reed; not only is it spiral, but also much narrower 
at one end than at the other; it is much too wide, in fact, to answer 
the purpose of the bee without alteration, or some mode of adaptation, 
